Knowledge

Ensemble (mathematical physics)

Source 📝

1920:
example of this is a gas of identical particles whose state is written in terms of the particles' individual positions and momenta: when two particles are exchanged, the resulting point in phase space is different, and yet it corresponds to an identical physical state of the system. It is important in statistical mechanics (a theory about physical states) to recognize that the phase space is just a mathematical construction, and to not naively overcount actual physical states when integrating over phase space. Overcounting can cause serious problems:
3777: 466: 49: 2717: 517:) —a statistical ensemble where the total energy of the system and the number of particles in the system are each fixed to particular values; each of the members of the ensemble are required to have the same total energy and particle number. The system must remain totally isolated (unable to exchange energy or particles with its environment) in order to stay in statistical equilibrium. 2499: 3432:
Technically, there are some phases where the permutation of particles does not even yield a distinct specific phase: for example, two similar particles can share the exact same trajectory, internal state, etc.. However, in classical mechanics these phases only make up an infinitesimal fraction of the
498:"We may imagine a great number of systems of the same nature, but differing in the configurations and velocities which they have at a given instant, and differing in not merely infinitesimally, but it may be so as to embrace every conceivable combination of configuration and velocities..." J. W. Gibbs 492:
The study of thermodynamics is concerned with systems that appear to human perception to be "static" (despite the motion of their internal parts), and which can be described simply by a set of macroscopically observable variables. These systems can be described by statistical ensembles that depend on
415:
The concept of an equilibrium or stationary ensemble is crucial to many applications of statistical ensembles. Although a mechanical system certainly evolves over time, the ensemble does not necessarily have to evolve. In fact, the ensemble will not evolve if it contains all past and future phases of
3024:
for a system in a physics lab: For example, the procedure might involve a physical apparatus and some protocols for manipulating the apparatus. As a result of this preparation procedure, some system is produced and maintained in isolation for some small period of time. By repeating this laboratory
1919:
Typically, the phase space contains duplicates of the same physical state in multiple distinct locations. This is a consequence of the way that a physical state is encoded into mathematical coordinates; the simplest choice of coordinate system often allows a state to be encoded in multiple ways. An
1991:
As mentioned above, the classic example of this overcounting is for a fluid system containing various kinds of particles, where any two particles of the same kind are indistinguishable and exchangeable. When the state is written in terms of the particles' individual positions and momenta, then the
1792:
over microstates, it is necessary to somehow partition the phase space into blocks that are distributed representing the different states of the system in a fair way. It turns out that the correct way to do this simply results in equal-sized blocks of canonical phase space, and so a microstate in
1981:
introduced above, which is a whole number that represents how many ways a physical state can be represented in phase space. Its value does not vary with the continuous canonical coordinates, so overcounting can be corrected simply by integrating over the full range of canonical coordinates, then
559:
The calculations that can be made using each of these ensembles are explored further in their respective articles. Other thermodynamic ensembles can be also defined, corresponding to different physical requirements, for which analogous formulae can often similarly be derived. For example, in the
554:
are specified. The grand canonical ensemble is appropriate for describing an open system: one which is in, or has been in, weak contact with a reservoir (thermal contact, chemical contact, radiative contact, electrical contact, etc.). The ensemble remains in statistical equilibrium if the system
1397:
If the number of parts in the system is allowed to vary among the systems in the ensemble (as in a grand ensemble where the number of particles is a random quantity), then it is a probability distribution over an extended phase space that includes further variables such as particle numbers
1649: 368:, considered all at once, each of which represents a possible state that the real system might be in. In other words, a statistical ensemble is a set of systems of particles used in statistical mechanics to describe a single system. The concept of an ensemble was introduced by 2216: 1950:
A crude way to remove the overcounting would be to manually define a subregion of phase space that includes each physical state only once and then exclude all other parts of phase space. In a gas, for example, one could include only those phases where the particles'
726:. The density matrix provides a fully general tool that can incorporate both quantum uncertainties (present even if the state of the system were completely known) and classical uncertainties (due to a lack of knowledge) in a unified manner. Any physical observable 1779: 3221: 537:
with a heat bath. In order to be in statistical equilibrium, the system must remain totally closed (unable to exchange particles with its environment) and may come into weak thermal contact with other systems that are described by ensembles with the same
407:
properties. For many important physical cases, it is possible to calculate averages directly over the whole of the thermodynamic ensemble, to obtain explicit formulas for many of the thermodynamic quantities of interest, often in terms of the appropriate
1946:
It is in general difficult to find a coordinate system that uniquely encodes each physical state. As a result, it is usually necessary to use a coordinate system with multiple copies of each state, and then to recognize and remove the overcounting.
2905: 391:
The ensemble formalises the notion that an experimenter repeating an experiment again and again under the same macroscopic conditions, but unable to control the microscopic details, may expect to observe a range of different outcomes.
1228: 3354:, i. e., the principle of conservation of extension in canonical phase space for Hamiltonian mechanics. This can also be demonstrated starting with the conception of an ensemble as a multitude of systems. See Gibbs' 3597:
Heath Turner, C.; Brennan, John K.; LĂ­sal, Martin; Smith, William R.; Karl Johnson, J.; Gubbins, Keith E. (2008). "Simulation of chemical reaction equilibria by the reaction ensemble Monte Carlo method: a review".
843: 2990:
In the discussion given so far, while rigorous, we have taken for granted that the notion of an ensemble is valid a priori, as is commonly done in physical context. What has not been shown is that the ensemble
1957:
coordinates are sorted in ascending order. While this would solve the problem, the resulting integral over phase space would be tedious to perform due to its unusual boundary shape. (In this case, the factor
1518: 1974:
A simpler way to correct the overcounting is to integrate over all of phase space but to reduce the weight of each phase in order to exactly compensate the overcounting. This is accomplished by the factor
493:
a few observable parameters, and which are in statistical equilibrium. Gibbs noted that different macroscopic constraints lead to different types of ensembles, with particular statistical characteristics.
588:
The precise mathematical expression for a statistical ensemble has a distinct form depending on the type of mechanics under consideration (quantum or classical). In the classical case, the ensemble is a
2494:{\displaystyle {\bar {A}}={\frac {\int {Ae^{-\beta H(q_{1},q_{2},\dots ,q_{M},p_{1},p_{2},\dots ,p_{N})}\,d\tau }}{\int {e^{-\beta H(q_{1},q_{2},\dots ,q_{M},p_{1},p_{2},\dots ,p_{N})}\,d\tau }}},} 3292: 1001: 1259: 1660: 1924:
Dependence of derived quantities (such as entropy and chemical potential) on the choice of coordinate system, since one coordinate system might show more or less overcounting than another.
2061: 1857: 3119: 1793:
classical mechanics is an extended region in the phase space of canonical coordinates that has a particular volume. In particular, the probability density function in phase space,
1060: 960: 1506:
can be written as a function of the system's phase. The expectation value of any such quantity is given by an integral over the entire phase space of this quantity weighted by
2592: 915: 724: 3234:
questions to the lattice of closed subspaces of a Hilbert space. With some additional technical assumptions one can then infer that states are given by density operators
2534: 1126: 1097: 875: 757: 17: 2791: 2685: 2560: 2660: 2633: 777: 379:
is a specific variety of statistical ensemble that, among other properties, is in statistical equilibrium (defined below), and is used to derive the properties of
4098: 3738: 605:; the microstates are the result of partitioning phase space into equal-sized units, although the size of these units can be chosen somewhat arbitrarily. 1784:
Phase space is a continuous space containing an infinite number of distinct physical states within any small region. In order to connect the probability
3409:—each physical orientation can be encoded in two ways. If this encoding is used without correcting the overcounting, then the entropy will be higher by 3374:, leading to unit-dependence in the values of some thermodynamic quantities like entropy and chemical potential. Since the advent of quantum mechanics, 1142: 2084:
The formulation of statistical ensembles used in physics has now been widely adopted in other fields, in part because it has been recognized that the
2738: 2123:
by means of nearest-neighbor interactions between spins. The statistical formulation of the principle of locality is now seen to be a form of the
3297:
We see this reflects the definition of quantum states in general: A quantum state is a mapping from the observables to their expectation values.
335: 3507: 1099:(Hamiltonian). The grand canonical ensemble is additionally a function of the particle number, measured by the total particle number operator 789: 3793: 2171: 2164: 1988:
does vary strongly with discrete variables such as numbers of particles, and so it must be applied before summing over particle numbers.
129: 1644:{\displaystyle \langle X\rangle =\sum _{N_{1}=0}^{\infty }\ldots \sum _{N_{s}=0}^{\infty }\int \ldots \int \rho X\,dp_{1}\ldots dq_{n}.} 3798: 3731: 2696: 1905:
influences the offsets of quantities such as entropy and chemical potential, and so it is important to be consistent with the value of
3052:
sequence of systems. The systems are similar in that they were all produced in the same way. This infinite sequence is an ensemble.
3063:. Again, the testing procedure involves a physical apparatus and some protocols; as a result of the testing procedure we obtain a 1250:, are the elements of a complete and orthogonal basis. (Note that in other bases, the density matrix is not necessarily diagonal.) 529:)—a statistical ensemble where the energy is not known exactly but the number of particles is fixed. In place of the energy, the 580:, deviations to this rule occurs under conditions that state-variables are non-convex, such as small molecular measurements. 3724: 598: 555:
comes into weak contact with other systems that are described by ensembles with the same temperature and chemical potential.
3351: 3321: 1287: 3244: 965: 328: 3467: 2160: 1774:{\displaystyle \sum _{N_{1}=0}^{\infty }\ldots \sum _{N_{s}=0}^{\infty }\int \ldots \int \rho \,dp_{1}\ldots dq_{n}=1.} 1434: 1353: 400: 163: 2781:, for a quantum system in thermal equilibrium with its environment, the weighted average takes the form of a sum over 1889:
is an overcounting correction factor (see below), generally dependent on the number of particles and similar concerns.
3566: 3538: 2764: 550:)—a statistical ensemble where neither the energy nor particle number are fixed. In their place, the temperature and 533:
is specified. The canonical ensemble is appropriate for describing a closed system which is in, or has been in, weak
2746: 3326: 2916: 409: 171: 91: 3216:{\displaystyle \sigma (E)=\lim _{N\rightarrow \infty }{\frac {1}{N}}\sum _{k=1}^{N}\operatorname {Meas} (E,X_{k})} 1998: 1811: 4093: 3992: 2742: 1278:
In classical mechanics, an ensemble is represented by a probability density function defined over the system's
486: 321: 4088: 2778: 396: 3761: 2093: 2075: 482: 96: 1016: 924: 693:
A statistical ensemble in quantum mechanics (also known as a mixed state) is most often represented by a
86: 81: 3869: 3785: 3512: 3311: 2187: 101: 2565: 364:) is an idealization consisting of a large number of virtual copies (sometimes infinitely many) of a 31: 1899:
can be chosen arbitrarily, the notional size of a microstate is also arbitrary. Still, the value of
884: 700: 4045: 4028: 3711: 3634: 3331: 2967: 2727: 2183: 2111:: that all interactions are only between neighboring atoms or nearby molecules. Thus, for example, 1939: 590: 542: 478: 442: 155: 3680: 3892: 3882: 3808: 2935: 2731: 2131:. Thus, the general notion of a statistical ensemble with nearest-neighbor interactions leads to 2112: 1303: 1283: 1063: 577: 509: 470: 217: 139: 63: 3423:. This does not actually lead to any observable error since it only causes unobservable offsets. 2510: 1102: 1073: 851: 733: 3939: 2900:{\displaystyle {\bar {A}}={\frac {\sum _{i}A_{i}e^{-\beta E_{i}}}{\sum _{i}e^{-\beta E_{i}}}}.} 2120: 780: 614: 1132:
in the orthogonal basis of states that simultaneously diagonalize each conserved variable. In
3824: 3747: 3434: 3406: 2924: 2605: 2148: 2108: 1294: 1263: 353: 234: 40: 2667: 2545: 601:. In classical mechanics, the ensemble is instead written as a probability distribution in 3967: 3502: 3395:
choice of coordinate system used for representing orientations of three-dimensional objects
2638: 2611: 1433:
is how many different kinds of particles there are). The ensemble is then represented by a
1133: 1070:
are strictly functions of the total energy, which is measured by the total energy operator
1007: 762: 560:
reaction ensemble, particle number fluctuations are only allowed to occur according to the
380: 277: 8: 4033: 4012: 2995:(not the consequent results) is a precisely defined object mathematically. For instance, 2199: 2179: 2132: 2092:
serves to maximize the entropy of a system, subject to a set of constraints: this is the
2079: 434: 272: 262: 74: 448:
The term "ensemble" is often used in physics and the physics-influenced literature. In
4060: 3972: 3949: 3930: 3910: 3874: 3646: 2951: 2920: 2782: 2595: 2085: 1935: 1331: 1274:(red curve, lower figure). The initially compact ensemble becomes swirled up over time. 1067: 551: 521: 474: 449: 416:
the system. Such a statistical ensemble, one that does not change over time, is called
147: 3055:
In a laboratory setting, each one of these prepped systems might be used as input for
2919:
provides the complete framework for working with ensemble averages in thermodynamics,
4065: 3962: 3935: 3846: 3836: 3829: 3803: 3615: 3562: 3534: 3463: 2928: 2178:
obtained for a given physical quantity does not depend on the ensemble chosen at the
2163:
of a system, according to the distribution of the system on its micro-states in this
676: 613:
Putting aside for the moment the question of how statistical ensembles are generated
565: 453: 297: 239: 3957: 3656: 3607: 2174:
chosen, its mathematical expression varies from ensemble to ensemble. However, the
2136: 594: 292: 267: 116: 4007: 1992:
overcounting related to the exchange of identical particles is corrected by using
1971:, and the integral would be restricted to the selected subregion of phase space.) 1223:{\displaystyle {\hat {\rho }}=\sum _{i}P_{i}|\psi _{i}\rangle \langle \psi _{i}|,} 4002: 3997: 3925: 3920: 3887: 3814: 3394: 3381: 2124: 1129: 576:
In thermodynamic limit all ensembles should produce identical observables due to
534: 282: 244: 224: 1927:
Erroneous conclusions that are inconsistent with physical experience, as in the
4050: 3766: 3660: 3526: 3306: 2688: 2128: 1928: 1271: 1062:) can be written solely as a function of conserved variables. For example, the 1003:(this essentially is the condition that the probabilities must add up to one). 694: 688: 287: 194: 106: 58: 3611: 4082: 4038: 3619: 3227: 2089: 1258: 561: 369: 597:, is a way of assigning a probability distribution over the results of each 395:
The notional size of ensembles in thermodynamics, statistical mechanics and
4055: 3004: 1875:, setting the extent of the microstate and providing correct dimensions to 307: 3437:
zero) and so they do not contribute to any volume integral in phase space.
469:
Visual representation of five statistical ensembles (from left to right):
3864: 3859: 3384:
in order to obtain a semiclassical correspondence with quantum mechanics.
3316: 2207: 2116: 2097: 1279: 1270:(top). Each system consists of one massive particle in a one-dimensional 1267: 617:, we should be able to perform the following two operations on ensembles 602: 530: 438: 404: 302: 204: 199: 189: 3716: 465: 3854: 3554: 3402: 918: 838:{\displaystyle \langle X\rangle =\operatorname {Tr} ({\hat {X}}\rho ).} 3075:
applied to each prepared system, we obtain a sequence of values Meas (
48: 3915: 1286:, the density function (the ensemble) evolves over time according to 759:. The expectation value of this operator on the statistical ensemble 3226:
For quantum mechanical systems, an important assumption made in the
2716: 437:
from the full set of possible states. For example, a collection of
433:
The word "ensemble" is also used for a smaller set of possibilities
3819: 3398: 3049: 2107:
In addition, statistical ensembles in physics are often built on a
2101: 878: 229: 3651: 3393:
In some cases the overcounting error is benign. An example is the
3984: 593:
over the microstates. In quantum mechanics, this notion, due to
349: 3017:
In this section, we attempt to partially answer this question.
2958:) with its surroundings (usually a heat bath), but the volume ( 1799:, is related to the probability distribution over microstates, 504:
Three important thermodynamic ensembles were defined by Gibbs:
365: 1654:
The condition of probability normalization applies, requiring
3596: 1871:
is an arbitrary but predetermined constant with the units of
679:
of statistical ensembles have the structure of a convex set.
652:, then produce a new ensemble by probabilistic sampling from 111: 2096:. This principle has now been widely applied to problems in 1006:
In general, the ensemble evolves over time according to the
3712:
Monte Carlo applet applied in statistical physics problems.
3533:. San Francisco: W.H. Freeman and Company. pp. 31 ff. 3367:(Historical note) Gibbs' original ensemble effectively set 2608:
of the classical system in terms of the set of coordinates
2175: 2156: 1013:
Equilibrium ensembles (those that do not evolve over time,
3110:). Each one of these values is a 0 (or no) or a 1 (yes). 3048:, which in our mathematical idealization, we assume is an 962:), etc. The density matrix must always have a trace of 1: 445:
iteration is called an ensemble in some of the literature.
3635:""Ensemble inequivalence in single-molecule experiments"" 3416:
per rotatable object and the chemical potential lower by
1982:
dividing the result by the overcounting factor. However,
1914: 3688:
George Mason University Physics and Astronomy Department
3230:
approach to quantum mechanics is the identification of
3013:
It is not clear how to physically generate an ensemble.
2135:, which again find broad applicability; for example in 3025:
preparation procedure we obtain a sequence of systems
2954:
represents a closed system which can exchange energy (
27:
Idealization of a large number of atomic-sized systems
3525: 3247: 3122: 2970:
represents an open system which can exchange energy (
2794: 2670: 2641: 2614: 2568: 2548: 2513: 2219: 2001: 1814: 1663: 1521: 1145: 1105: 1076: 1019: 968: 927: 887: 854: 792: 765: 736: 703: 403:
the system could be in, consistent with its observed
3553: 1297:
with a defined number of parts, the phase space has
730:
in quantum mechanics can be written as an operator,
3350:This equal-volume partitioning is a consequence of 3287:{\displaystyle \sigma (E)=\operatorname {Tr} (ES).} 2695:The denominator in this expression is known as the 996:{\displaystyle \operatorname {Tr} {\hat {\rho }}=1} 608: 3457: 3451: 3286: 3215: 2899: 2679: 2654: 2627: 2586: 2554: 2528: 2493: 2193: 2055: 1851: 1773: 1643: 1282:. While an individual system evolves according to 1222: 1120: 1091: 1054: 995: 954: 909: 869: 837: 771: 751: 718: 383:from the laws of classical or quantum mechanics. 4080: 3139: 2706: 848:This can be used to evaluate averages (operator 2938:represents an isolated system in which energy ( 2536:is the ensemble average of the system property 2170:Since the ensemble average is dependent on the 2066:This is known as "correct Boltzmann counting". 3508:Elementary Principles in Statistical Mechanics 2127:in the broad sense; nearest neighbors are now 4099:Philosophy of thermal and statistical physics 3732: 3632: 3586:. Green & Co, London, New York: Longmans. 2985: 2910: 329: 3681:"Statistical mechanics of classical systems" 2056:{\displaystyle C=N_{1}!N_{2}!\ldots N_{s}!.} 1528: 1522: 1199: 1196: 799: 793: 399:can be very large, including every possible 2745:. Unsourced material may be challenged and 1852:{\displaystyle \rho ={\frac {1}{h^{n}C}}P,} 1416:(second kind of particle), and so on up to 18:Statistical ensemble (mathematical physics) 3739: 3725: 3633:SĂŒzen, M; Sega, M; Holm, C (18 May 2009). 3113:Assume the following time average exists: 2069: 386: 336: 322: 47: 3746: 3650: 2978:) with its surroundings, but the volume ( 2765:Learn how and when to remove this message 2691:of the classical phase space of interest. 2477: 2354: 1735: 1608: 2635:and their conjugate generalized momenta 2159:of a quantity that is a function of the 1352:. The ensemble is then represented by a 1257: 464: 3497: 3495: 3493: 3491: 3489: 3487: 3485: 3483: 3481: 3479: 2206:takes the form of an integral over the 1253: 14: 4081: 3458:Rennie, Richard; Jonathan Law (2019). 1915:Correcting overcounting in phase space 1497:varies with the numbers of particles. 3720: 3626: 3581: 3547: 3519: 3501: 2785:, rather than a continuous integral: 682: 675:Under certain conditions, therefore, 599:complete set of commuting observables 3476: 2743:adding citations to reliable sources 2710: 1934:Foundational issues in defining the 1055:{\displaystyle d{\hat {\rho }}/dt=0} 955:{\displaystyle {\hat {X}}{\hat {Y}}} 245:Grand potential / Landau free energy 2142: 1128:. Such equilibrium ensembles are a 24: 3606:(2). Informa UK Limited: 119–146. 3380:is often taken to be equal to the 3149: 3071:answer. Given a testing procedure 1911:when comparing different systems. 1718: 1687: 1588: 1557: 1435:joint probability density function 1354:joint probability density function 583: 568:which are present in the system. 25: 4110: 3705: 3561:. Pergamon Press. pp. 9 ff. 3322:Liouville's theorem (Hamiltonian) 1964:introduced above would be set to 3775: 2715: 1788:in phase space to a probability 609:Requirements for representations 3673: 3531:Thermal Physics, Second Edition 3426: 3387: 3008:of particles inside a container 2962:) and the number of particles ( 2946:) and the number of particles ( 2915:The generalized version of the 2587:{\displaystyle {\frac {1}{kT}}} 2194:Classical statistical mechanics 3590: 3575: 3361: 3344: 3278: 3269: 3257: 3251: 3210: 3191: 3146: 3132: 3126: 2801: 2520: 2472: 2382: 2349: 2259: 2226: 1213: 1182: 1152: 1112: 1083: 1029: 981: 946: 934: 910:{\displaystyle {\hat {X}}^{2}} 895: 861: 829: 820: 811: 743: 719:{\displaystyle {\hat {\rho }}} 710: 571: 487:isoenthalpic-isobaric ensemble 427: 13: 1: 3444: 3003:exists (for example, is it a 2779:quantum statistical mechanics 2707:Quantum statistical mechanics 2699:and is denoted by the letter 637:are statistically equivalent. 460: 397:quantum statistical mechanics 3762:Principle of maximum entropy 3460:Oxford Dictionary of Physics 3327:Maxwell–Boltzmann statistics 2094:principle of maximum entropy 2076:Principle of maximum entropy 1491:. The number of coordinates 1427:(the last kind of particle; 1262:Evolution of an ensemble of 483:isobaric-isothermal ensemble 7: 3584:The Collected Works, Vol. 2 3397:. A simple encoding is the 3300: 2999:It is not clear where this 644:is a real number such that 87:Indistinguishable particles 10: 4115: 3786:Statistical thermodynamics 3661:10.1103/PhysRevE.79.051118 3529:; Herbert Kroemer (1980). 3312:Ensemble (fluid mechanics) 2986:Operational interpretation 2911:Canonical ensemble average 2529:{\displaystyle {\bar {A}}} 2202:with its environment, the 2198:For a classical system in 2073: 1407:(first kind of particle), 1121:{\displaystyle {\hat {N}}} 1092:{\displaystyle {\hat {H}}} 870:{\displaystyle {\hat {X}}} 779:is given by the following 752:{\displaystyle {\hat {X}}} 686: 29: 4021: 3983: 3948: 3903: 3845: 3784: 3773: 3754: 3612:10.1080/08927020801986564 3557:; Lifshitz, E.M. (1980). 3001:very large set of systems 420:and can be said to be in 32:Ensemble (disambiguation) 4046:Condensed matter physics 4029:Statistical field theory 3337: 3332:Replication (statistics) 2968:grand canonical ensemble 2966:) are all constant. The 2950:) are all constant. The 2184:grand canonical ensemble 1940:grand canonical ensemble 1500:Any mechanical quantity 1136:, the density matrix is 591:probability distribution 543:Grand canonical ensemble 479:grand canonical ensemble 443:Markov chain Monte Carlo 3904:Mathematical approaches 3893:Lennard-Jones potential 3809:thermodynamic potential 3513:Charles Scribner's Sons 3433:phase space (they have 2936:microcanonical ensemble 2121:ferromagnetic materials 2070:Ensembles in statistics 1304:generalized coordinates 1064:microcanonical ensemble 510:Microcanonical ensemble 471:microcanonical ensemble 422:statistical equilibrium 387:Physical considerations 130:Thermodynamic ensembles 82:Spin–statistics theorem 3940:conformal field theory 3288: 3217: 3184: 2901: 2681: 2680:{\displaystyle d\tau } 2656: 2629: 2588: 2556: 2555:{\displaystyle \beta } 2530: 2495: 2057: 1853: 1775: 1722: 1691: 1645: 1592: 1561: 1275: 1224: 1122: 1093: 1056: 997: 956: 911: 871: 839: 773: 753: 720: 502: 489: 377:thermodynamic ensemble 4094:Statistical ensembles 3855:Ferromagnetism models 3748:Statistical mechanics 3503:Gibbs, Josiah Willard 3356:Elementary Principles 3289: 3218: 3164: 3022:preparation procedure 2925:statistical mechanics 2902: 2783:quantum energy states 2682: 2657: 2655:{\displaystyle p_{i}} 2630: 2628:{\displaystyle q_{i}} 2589: 2557: 2531: 2496: 2149:statistical mechanics 2109:principle of locality 2058: 1854: 1776: 1695: 1664: 1646: 1565: 1534: 1261: 1225: 1123: 1094: 1057: 998: 957: 912: 872: 840: 774: 772:{\displaystyle \rho } 754: 721: 495: 468: 381:thermodynamic systems 354:statistical mechanics 235:Helmholtz free energy 164:Isoenthalpic–isobaric 41:Statistical mechanics 4089:Equations of physics 3600:Molecular Simulation 3582:Gibbs, J.W. (1928). 3245: 3120: 2982:) is kept constant. 2792: 2739:improve this section 2668: 2639: 2612: 2566: 2546: 2511: 2217: 2186:is an example of an 2133:Markov random fields 1999: 1812: 1661: 1519: 1288:Liouville's equation 1284:Hamilton's equations 1254:Classical mechanical 1143: 1103: 1074: 1017: 1008:von Neumann equation 966: 925: 885: 852: 790: 763: 734: 701: 625:of the same system: 362:statistical ensemble 30:For other uses, see 4034:elementary particle 3799:partition functions 3559:Statistical Physics 3462:. pp. 458 ff. 3352:Liouville's theorem 2200:thermal equilibrium 2180:thermodynamic limit 2080:Markov random field 677:equivalence classes 578:Legendre transforms 172:Isothermal–isobaric 75:Particle statistics 4061:information theory 3968:correlation length 3963:Critical exponents 3950:Critical phenomena 3931:stochastic process 3911:Boltzmann equation 3804:equations of state 3284: 3213: 3153: 3020:Suppose we have a 2952:canonical ensemble 2921:information theory 2917:partition function 2897: 2867: 2822: 2697:partition function 2677: 2652: 2625: 2596:thermodynamic beta 2584: 2552: 2526: 2491: 2155:is defined as the 2086:canonical ensemble 2053: 1936:chemical potential 1849: 1771: 1641: 1276: 1220: 1170: 1118: 1089: 1068:canonical ensemble 1052: 993: 952: 907: 867: 835: 769: 749: 716: 683:Quantum mechanical 566:chemical reactions 552:chemical potential 522:Canonical ensemble 490: 475:canonical ensemble 456:is more prevalent. 450:probability theory 410:partition function 112:Anyonic statistics 4076: 4075: 4066:Boltzmann machine 3936:mean-field theory 3837:Maxwell relations 3639:Physical Review E 3162: 3138: 3061:testing procedure 2974:) and particles ( 2929:quantum mechanics 2892: 2858: 2813: 2804: 2775: 2774: 2767: 2582: 2523: 2486: 2229: 2137:Hopfield networks 1841: 1332:canonical momenta 1295:mechanical system 1161: 1155: 1115: 1086: 1032: 984: 949: 937: 898: 864: 823: 746: 713: 664:with probability 656:with probability 454:probability space 401:microscopic state 346: 345: 240:Gibbs free energy 92:Maxwell–Boltzmann 16:(Redirected from 4106: 3958:Phase transition 3779: 3778: 3741: 3734: 3727: 3718: 3717: 3699: 3698: 3696: 3694: 3685: 3677: 3671: 3670: 3668: 3667: 3654: 3630: 3624: 3623: 3594: 3588: 3587: 3579: 3573: 3572: 3551: 3545: 3544: 3523: 3517: 3516: 3499: 3474: 3473: 3455: 3438: 3430: 3424: 3422: 3415: 3391: 3385: 3379: 3373: 3365: 3359: 3348: 3293: 3291: 3290: 3285: 3222: 3220: 3219: 3214: 3209: 3208: 3183: 3178: 3163: 3155: 3152: 2906: 2904: 2903: 2898: 2893: 2891: 2890: 2889: 2888: 2887: 2866: 2856: 2855: 2854: 2853: 2852: 2832: 2831: 2821: 2811: 2806: 2805: 2797: 2770: 2763: 2759: 2756: 2750: 2719: 2711: 2686: 2684: 2683: 2678: 2661: 2659: 2658: 2653: 2651: 2650: 2634: 2632: 2631: 2626: 2624: 2623: 2593: 2591: 2590: 2585: 2583: 2581: 2570: 2561: 2559: 2558: 2553: 2535: 2533: 2532: 2527: 2525: 2524: 2516: 2500: 2498: 2497: 2492: 2487: 2485: 2484: 2476: 2475: 2471: 2470: 2452: 2451: 2439: 2438: 2426: 2425: 2407: 2406: 2394: 2393: 2362: 2361: 2353: 2352: 2348: 2347: 2329: 2328: 2316: 2315: 2303: 2302: 2284: 2283: 2271: 2270: 2236: 2231: 2230: 2222: 2204:ensemble average 2153:ensemble average 2143:Ensemble average 2104:, and the like. 2062: 2060: 2059: 2054: 2046: 2045: 2030: 2029: 2017: 2016: 1987: 1980: 1970: 1963: 1956: 1910: 1904: 1898: 1888: 1880: 1874: 1870: 1858: 1856: 1855: 1850: 1842: 1840: 1836: 1835: 1822: 1804: 1798: 1780: 1778: 1777: 1772: 1764: 1763: 1748: 1747: 1721: 1716: 1709: 1708: 1690: 1685: 1678: 1677: 1650: 1648: 1647: 1642: 1637: 1636: 1621: 1620: 1591: 1586: 1579: 1578: 1560: 1555: 1548: 1547: 1511: 1505: 1496: 1490: 1432: 1426: 1415: 1406: 1393: 1351: 1329: 1323: 1302: 1249: 1245: 1229: 1227: 1226: 1221: 1216: 1211: 1210: 1195: 1194: 1185: 1180: 1179: 1169: 1157: 1156: 1148: 1134:bra–ket notation 1127: 1125: 1124: 1119: 1117: 1116: 1108: 1098: 1096: 1095: 1090: 1088: 1087: 1079: 1061: 1059: 1058: 1053: 1039: 1034: 1033: 1025: 1002: 1000: 999: 994: 986: 985: 977: 961: 959: 958: 953: 951: 950: 942: 939: 938: 930: 921:(using operator 916: 914: 913: 908: 906: 905: 900: 899: 891: 881:(using operator 876: 874: 873: 868: 866: 865: 857: 844: 842: 841: 836: 825: 824: 816: 778: 776: 775: 770: 758: 756: 755: 750: 748: 747: 739: 729: 725: 723: 722: 717: 715: 714: 706: 670: 651: 370:J. Willard Gibbs 338: 331: 324: 117:Braid statistics 51: 37: 36: 21: 4114: 4113: 4109: 4108: 4107: 4105: 4104: 4103: 4079: 4078: 4077: 4072: 4017: 3979: 3944: 3926:BBGKY hierarchy 3921:Vlasov equation 3899: 3888:depletion force 3881:Particles with 3841: 3780: 3776: 3771: 3750: 3745: 3708: 3703: 3702: 3692: 3690: 3683: 3679: 3678: 3674: 3665: 3663: 3631: 3627: 3595: 3591: 3580: 3576: 3569: 3552: 3548: 3541: 3527:Kittel, Charles 3524: 3520: 3500: 3477: 3470: 3456: 3452: 3447: 3442: 3441: 3431: 3427: 3417: 3410: 3392: 3388: 3382:Planck constant 3375: 3368: 3366: 3362: 3349: 3345: 3340: 3303: 3246: 3243: 3242: 3204: 3200: 3179: 3168: 3154: 3142: 3121: 3118: 3117: 3109: 3096: 3085: 3047: 3038: 3031: 2988: 2913: 2883: 2879: 2872: 2868: 2862: 2857: 2848: 2844: 2837: 2833: 2827: 2823: 2817: 2812: 2810: 2796: 2795: 2793: 2790: 2789: 2771: 2760: 2754: 2751: 2736: 2720: 2709: 2669: 2666: 2665: 2646: 2642: 2640: 2637: 2636: 2619: 2615: 2613: 2610: 2609: 2574: 2569: 2567: 2564: 2563: 2547: 2544: 2543: 2515: 2514: 2512: 2509: 2508: 2466: 2462: 2447: 2443: 2434: 2430: 2421: 2417: 2402: 2398: 2389: 2385: 2372: 2368: 2367: 2363: 2343: 2339: 2324: 2320: 2311: 2307: 2298: 2294: 2279: 2275: 2266: 2262: 2249: 2245: 2241: 2237: 2235: 2221: 2220: 2218: 2215: 2214: 2210:of the system: 2196: 2145: 2129:Markov blankets 2125:Markov property 2082: 2074:Main articles: 2072: 2041: 2037: 2025: 2021: 2012: 2008: 2000: 1997: 1996: 1983: 1976: 1965: 1959: 1952: 1917: 1906: 1900: 1894: 1884: 1876: 1872: 1866: 1831: 1827: 1826: 1821: 1813: 1810: 1809: 1800: 1794: 1759: 1755: 1743: 1739: 1717: 1704: 1700: 1699: 1686: 1673: 1669: 1668: 1662: 1659: 1658: 1632: 1628: 1616: 1612: 1587: 1574: 1570: 1569: 1556: 1543: 1539: 1538: 1520: 1517: 1516: 1507: 1501: 1492: 1488: 1479: 1472: 1463: 1456: 1447: 1437: 1428: 1425: 1417: 1414: 1408: 1405: 1399: 1391: 1382: 1375: 1366: 1356: 1350: 1341: 1335: 1325: 1322: 1313: 1307: 1298: 1256: 1247: 1243: 1234: 1212: 1206: 1202: 1190: 1186: 1181: 1175: 1171: 1165: 1147: 1146: 1144: 1141: 1140: 1130:diagonal matrix 1107: 1106: 1104: 1101: 1100: 1078: 1077: 1075: 1072: 1071: 1035: 1024: 1023: 1018: 1015: 1014: 976: 975: 967: 964: 963: 941: 940: 929: 928: 926: 923: 922: 901: 890: 889: 888: 886: 883: 882: 856: 855: 853: 850: 849: 815: 814: 791: 788: 787: 764: 761: 760: 738: 737: 735: 732: 731: 727: 705: 704: 702: 699: 698: 691: 685: 665: 645: 611: 586: 584:Representations 574: 535:thermal contact 463: 430: 389: 352:, specifically 342: 313: 312: 258: 250: 249: 225:Internal energy 220: 210: 209: 185: 177: 176: 156:Grand canonical 132: 122: 121: 77: 35: 28: 23: 22: 15: 12: 11: 5: 4112: 4102: 4101: 4096: 4091: 4074: 4073: 4071: 4070: 4069: 4068: 4063: 4058: 4051:Complex system 4048: 4043: 4042: 4041: 4036: 4025: 4023: 4019: 4018: 4016: 4015: 4010: 4005: 4000: 3995: 3989: 3987: 3981: 3980: 3978: 3977: 3976: 3975: 3970: 3960: 3954: 3952: 3946: 3945: 3943: 3942: 3933: 3928: 3923: 3918: 3913: 3907: 3905: 3901: 3900: 3898: 3897: 3896: 3895: 3890: 3879: 3878: 3877: 3872: 3867: 3862: 3851: 3849: 3843: 3842: 3840: 3839: 3834: 3833: 3832: 3827: 3822: 3817: 3806: 3801: 3796: 3790: 3788: 3782: 3781: 3774: 3772: 3770: 3769: 3767:ergodic theory 3764: 3758: 3756: 3752: 3751: 3744: 3743: 3736: 3729: 3721: 3715: 3714: 3707: 3706:External links 3704: 3701: 3700: 3672: 3625: 3589: 3574: 3567: 3546: 3539: 3518: 3475: 3469:978-0198821472 3468: 3449: 3448: 3446: 3443: 3440: 3439: 3425: 3386: 3360: 3342: 3341: 3339: 3336: 3335: 3334: 3329: 3324: 3319: 3314: 3309: 3307:Density matrix 3302: 3299: 3295: 3294: 3283: 3280: 3277: 3274: 3271: 3268: 3265: 3262: 3259: 3256: 3253: 3250: 3224: 3223: 3212: 3207: 3203: 3199: 3196: 3193: 3190: 3187: 3182: 3177: 3174: 3171: 3167: 3161: 3158: 3151: 3148: 3145: 3141: 3137: 3134: 3131: 3128: 3125: 3105: 3097:), ..., Meas ( 3094: 3083: 3043: 3036: 3029: 3015: 3014: 3011: 2987: 2984: 2912: 2909: 2908: 2907: 2896: 2886: 2882: 2878: 2875: 2871: 2865: 2861: 2851: 2847: 2843: 2840: 2836: 2830: 2826: 2820: 2816: 2809: 2803: 2800: 2773: 2772: 2723: 2721: 2714: 2708: 2705: 2693: 2692: 2689:volume element 2676: 2673: 2663: 2649: 2645: 2622: 2618: 2599: 2580: 2577: 2573: 2551: 2541: 2522: 2519: 2502: 2501: 2490: 2483: 2480: 2474: 2469: 2465: 2461: 2458: 2455: 2450: 2446: 2442: 2437: 2433: 2429: 2424: 2420: 2416: 2413: 2410: 2405: 2401: 2397: 2392: 2388: 2384: 2381: 2378: 2375: 2371: 2366: 2360: 2357: 2351: 2346: 2342: 2338: 2335: 2332: 2327: 2323: 2319: 2314: 2310: 2306: 2301: 2297: 2293: 2290: 2287: 2282: 2278: 2274: 2269: 2265: 2261: 2258: 2255: 2252: 2248: 2244: 2240: 2234: 2228: 2225: 2195: 2192: 2144: 2141: 2115:, such as the 2113:lattice models 2071: 2068: 2064: 2063: 2052: 2049: 2044: 2040: 2036: 2033: 2028: 2024: 2020: 2015: 2011: 2007: 2004: 1944: 1943: 1932: 1929:mixing paradox 1925: 1916: 1913: 1891: 1890: 1882: 1860: 1859: 1848: 1845: 1839: 1834: 1830: 1825: 1820: 1817: 1782: 1781: 1770: 1767: 1762: 1758: 1754: 1751: 1746: 1742: 1738: 1734: 1731: 1728: 1725: 1720: 1715: 1712: 1707: 1703: 1698: 1694: 1689: 1684: 1681: 1676: 1672: 1667: 1652: 1651: 1640: 1635: 1631: 1627: 1624: 1619: 1615: 1611: 1607: 1604: 1601: 1598: 1595: 1590: 1585: 1582: 1577: 1573: 1568: 1564: 1559: 1554: 1551: 1546: 1542: 1537: 1533: 1530: 1527: 1524: 1484: 1477: 1468: 1461: 1452: 1445: 1421: 1412: 1403: 1387: 1380: 1371: 1364: 1346: 1339: 1318: 1311: 1272:potential well 1255: 1252: 1239: 1231: 1230: 1219: 1215: 1209: 1205: 1201: 1198: 1193: 1189: 1184: 1178: 1174: 1168: 1164: 1160: 1154: 1151: 1114: 1111: 1085: 1082: 1051: 1048: 1045: 1042: 1038: 1031: 1028: 1022: 992: 989: 983: 980: 974: 971: 948: 945: 936: 933: 904: 897: 894: 863: 860: 846: 845: 834: 831: 828: 822: 819: 813: 810: 807: 804: 801: 798: 795: 768: 745: 742: 712: 709: 695:density matrix 689:Density matrix 687:Main article: 684: 681: 673: 672: 638: 610: 607: 585: 582: 573: 570: 557: 556: 539: 518: 462: 459: 458: 457: 446: 429: 426: 388: 385: 344: 343: 341: 340: 333: 326: 318: 315: 314: 311: 310: 305: 300: 295: 290: 285: 280: 275: 270: 265: 259: 256: 255: 252: 251: 248: 247: 242: 237: 232: 227: 221: 216: 215: 212: 211: 208: 207: 202: 197: 192: 186: 183: 182: 179: 178: 175: 174: 166: 158: 150: 142: 140:Microcanonical 133: 128: 127: 124: 123: 120: 119: 114: 109: 107:Parastatistics 104: 99: 94: 89: 84: 78: 73: 72: 69: 68: 67: 66: 64:Kinetic theory 61: 59:Thermodynamics 53: 52: 44: 43: 26: 9: 6: 4: 3: 2: 4111: 4100: 4097: 4095: 4092: 4090: 4087: 4086: 4084: 4067: 4064: 4062: 4059: 4057: 4054: 4053: 4052: 4049: 4047: 4044: 4040: 4039:superfluidity 4037: 4035: 4032: 4031: 4030: 4027: 4026: 4024: 4020: 4014: 4011: 4009: 4006: 4004: 4001: 3999: 3996: 3994: 3991: 3990: 3988: 3986: 3982: 3974: 3971: 3969: 3966: 3965: 3964: 3961: 3959: 3956: 3955: 3953: 3951: 3947: 3941: 3937: 3934: 3932: 3929: 3927: 3924: 3922: 3919: 3917: 3914: 3912: 3909: 3908: 3906: 3902: 3894: 3891: 3889: 3886: 3885: 3884: 3880: 3876: 3873: 3871: 3868: 3866: 3863: 3861: 3858: 3857: 3856: 3853: 3852: 3850: 3848: 3844: 3838: 3835: 3831: 3828: 3826: 3823: 3821: 3818: 3816: 3813: 3812: 3810: 3807: 3805: 3802: 3800: 3797: 3795: 3792: 3791: 3789: 3787: 3783: 3768: 3765: 3763: 3760: 3759: 3757: 3753: 3749: 3742: 3737: 3735: 3730: 3728: 3723: 3722: 3719: 3713: 3710: 3709: 3689: 3682: 3676: 3662: 3658: 3653: 3648: 3645:(5): 051118. 3644: 3640: 3636: 3629: 3621: 3617: 3613: 3609: 3605: 3601: 3593: 3585: 3578: 3570: 3568:0-08-023038-5 3564: 3560: 3556: 3550: 3542: 3540:0-7167-1088-9 3536: 3532: 3528: 3522: 3514: 3510: 3509: 3504: 3498: 3496: 3494: 3492: 3490: 3488: 3486: 3484: 3482: 3480: 3471: 3465: 3461: 3454: 3450: 3436: 3429: 3420: 3413: 3408: 3405:) which is a 3404: 3401:(e. g., unit 3400: 3396: 3390: 3383: 3378: 3371: 3364: 3357: 3353: 3347: 3343: 3333: 3330: 3328: 3325: 3323: 3320: 3318: 3315: 3313: 3310: 3308: 3305: 3304: 3298: 3281: 3275: 3272: 3266: 3263: 3260: 3254: 3248: 3241: 3240: 3239: 3237: 3233: 3229: 3228:quantum logic 3205: 3201: 3197: 3194: 3188: 3185: 3180: 3175: 3172: 3169: 3165: 3159: 3156: 3143: 3135: 3129: 3123: 3116: 3115: 3114: 3111: 3108: 3104: 3100: 3093: 3089: 3082: 3078: 3074: 3070: 3066: 3062: 3058: 3053: 3051: 3046: 3042: 3035: 3028: 3023: 3018: 3012: 3009: 3007: 3002: 2998: 2997: 2996: 2994: 2983: 2981: 2977: 2973: 2969: 2965: 2961: 2957: 2953: 2949: 2945: 2941: 2937: 2932: 2930: 2926: 2922: 2918: 2894: 2884: 2880: 2876: 2873: 2869: 2863: 2859: 2849: 2845: 2841: 2838: 2834: 2828: 2824: 2818: 2814: 2807: 2798: 2788: 2787: 2786: 2784: 2780: 2769: 2766: 2758: 2755:November 2023 2748: 2744: 2740: 2734: 2733: 2729: 2724:This section 2722: 2718: 2713: 2712: 2704: 2702: 2698: 2690: 2674: 2671: 2664: 2647: 2643: 2620: 2616: 2607: 2603: 2600: 2597: 2578: 2575: 2571: 2549: 2542: 2539: 2517: 2507: 2506: 2505: 2488: 2481: 2478: 2467: 2463: 2459: 2456: 2453: 2448: 2444: 2440: 2435: 2431: 2427: 2422: 2418: 2414: 2411: 2408: 2403: 2399: 2395: 2390: 2386: 2379: 2376: 2373: 2369: 2364: 2358: 2355: 2344: 2340: 2336: 2333: 2330: 2325: 2321: 2317: 2312: 2308: 2304: 2299: 2295: 2291: 2288: 2285: 2280: 2276: 2272: 2267: 2263: 2256: 2253: 2250: 2246: 2242: 2238: 2232: 2223: 2213: 2212: 2211: 2209: 2205: 2201: 2191: 2189: 2185: 2181: 2177: 2173: 2168: 2166: 2162: 2158: 2154: 2150: 2140: 2138: 2134: 2130: 2126: 2122: 2118: 2114: 2110: 2105: 2103: 2099: 2095: 2091: 2090:Gibbs measure 2087: 2081: 2077: 2067: 2050: 2047: 2042: 2038: 2034: 2031: 2026: 2022: 2018: 2013: 2009: 2005: 2002: 1995: 1994: 1993: 1989: 1986: 1979: 1972: 1968: 1962: 1955: 1948: 1941: 1937: 1933: 1930: 1926: 1923: 1922: 1921: 1912: 1909: 1903: 1897: 1887: 1883: 1879: 1869: 1865: 1864: 1863: 1846: 1843: 1837: 1832: 1828: 1823: 1818: 1815: 1808: 1807: 1806: 1803: 1797: 1791: 1787: 1768: 1765: 1760: 1756: 1752: 1749: 1744: 1740: 1736: 1732: 1729: 1726: 1723: 1713: 1710: 1705: 1701: 1696: 1692: 1682: 1679: 1674: 1670: 1665: 1657: 1656: 1655: 1638: 1633: 1629: 1625: 1622: 1617: 1613: 1609: 1605: 1602: 1599: 1596: 1593: 1583: 1580: 1575: 1571: 1566: 1562: 1552: 1549: 1544: 1540: 1535: 1531: 1525: 1515: 1514: 1513: 1510: 1504: 1498: 1495: 1487: 1483: 1476: 1471: 1467: 1460: 1455: 1451: 1444: 1440: 1436: 1431: 1424: 1420: 1411: 1402: 1395: 1390: 1386: 1379: 1374: 1370: 1363: 1359: 1355: 1349: 1345: 1338: 1333: 1328: 1321: 1317: 1310: 1305: 1301: 1296: 1291: 1289: 1285: 1281: 1273: 1269: 1265: 1260: 1251: 1246:, indexed by 1242: 1238: 1217: 1207: 1203: 1191: 1187: 1176: 1172: 1166: 1162: 1158: 1149: 1139: 1138: 1137: 1135: 1131: 1109: 1080: 1069: 1065: 1049: 1046: 1043: 1040: 1036: 1026: 1020: 1011: 1009: 1004: 990: 987: 978: 972: 969: 943: 931: 920: 902: 892: 880: 858: 832: 826: 817: 808: 805: 802: 796: 786: 785: 784: 782: 766: 740: 707: 697:, denoted by 696: 690: 680: 678: 669: 663: 659: 655: 649: 643: 639: 636: 632: 629:Test whether 628: 627: 626: 624: 620: 616: 615:operationally 606: 604: 600: 596: 592: 581: 579: 569: 567: 563: 562:stoichiometry 553: 549: 545: 544: 540: 536: 532: 528: 524: 523: 519: 516: 512: 511: 507: 506: 505: 501: 499: 494: 488: 484: 480: 476: 472: 467: 455: 451: 447: 444: 440: 436: 432: 431: 425: 423: 419: 413: 411: 406: 402: 398: 393: 384: 382: 378: 373: 371: 367: 363: 359: 355: 351: 339: 334: 332: 327: 325: 320: 319: 317: 316: 309: 306: 304: 301: 299: 296: 294: 291: 289: 286: 284: 281: 279: 276: 274: 271: 269: 266: 264: 261: 260: 254: 253: 246: 243: 241: 238: 236: 233: 231: 228: 226: 223: 222: 219: 214: 213: 206: 203: 201: 198: 196: 193: 191: 188: 187: 181: 180: 173: 170: 167: 165: 162: 159: 157: 154: 151: 149: 146: 143: 141: 138: 135: 134: 131: 126: 125: 118: 115: 113: 110: 108: 105: 103: 100: 98: 97:Bose–Einstein 95: 93: 90: 88: 85: 83: 80: 79: 76: 71: 70: 65: 62: 60: 57: 56: 55: 54: 50: 46: 45: 42: 39: 38: 33: 19: 4022:Applications 3973:size scaling 3691:. Retrieved 3687: 3675: 3664:. Retrieved 3642: 3638: 3628: 3603: 3599: 3592: 3583: 3577: 3558: 3555:Landau, L.D. 3549: 3530: 3521: 3511:. New York: 3506: 3459: 3453: 3428: 3418: 3411: 3407:double cover 3389: 3376: 3369: 3363: 3358:, Chapter I. 3355: 3346: 3296: 3235: 3231: 3225: 3112: 3106: 3102: 3098: 3091: 3087: 3080: 3076: 3072: 3068: 3064: 3060: 3056: 3054: 3044: 3040: 3033: 3026: 3021: 3019: 3016: 3005: 3000: 2992: 2989: 2979: 2975: 2971: 2963: 2959: 2955: 2947: 2943: 2939: 2933: 2914: 2776: 2761: 2752: 2737:Please help 2725: 2700: 2694: 2601: 2537: 2503: 2203: 2197: 2169: 2152: 2146: 2106: 2083: 2065: 1990: 1984: 1977: 1973: 1966: 1960: 1953: 1949: 1945: 1918: 1907: 1901: 1895: 1892: 1885: 1877: 1867: 1861: 1805:by a factor 1801: 1795: 1790:distribution 1789: 1785: 1783: 1653: 1508: 1502: 1499: 1493: 1485: 1481: 1474: 1469: 1465: 1458: 1453: 1449: 1442: 1438: 1429: 1422: 1418: 1409: 1400: 1396: 1388: 1384: 1377: 1372: 1368: 1361: 1357: 1347: 1343: 1336: 1326: 1319: 1315: 1308: 1299: 1292: 1277: 1240: 1236: 1232: 1012: 1005: 847: 692: 674: 667: 661: 657: 653: 647: 641: 634: 630: 622: 618: 612: 587: 575: 558: 548:ÎŒVT ensemble 547: 541: 538:temperature. 527:NVT ensemble 526: 520: 515:NVE ensemble 514: 508: 503: 497: 496: 491: 421: 417: 414: 394: 390: 376: 374: 361: 357: 347: 168: 160: 152: 144: 136: 4013:von Neumann 3883:force field 3875:percolation 3403:quaternions 3317:Phase space 3059:subsequent 2942:), volume ( 2606:Hamiltonian 2594:, known as 2208:phase space 2188:open system 2117:Ising model 2098:linguistics 1873:energy×time 1330:associated 1280:phase space 1268:phase space 1266:systems in 919:covariances 603:phase space 595:von Neumann 572:Equivalence 531:temperature 452:, the term 428:Terminology 405:macroscopic 293:von Neumann 102:Fermi–Dirac 4083:Categories 3870:Heisenberg 3693:3 November 3666:2024-03-03 3445:References 2161:microstate 1233:where the 461:Main types 418:stationary 257:Scientists 218:Potentials 3993:Boltzmann 3916:H-theorem 3794:Ensembles 3652:0810.3407 3620:0892-7022 3267:⁡ 3249:σ 3238:so that: 3189:⁡ 3166:∑ 3150:∞ 3147:→ 3124:σ 3086:), Meas ( 2877:β 2874:− 2860:∑ 2842:β 2839:− 2815:∑ 2802:¯ 2726:does not 2675:τ 2550:β 2521:¯ 2482:τ 2457:… 2412:… 2377:β 2374:− 2365:∫ 2359:τ 2334:… 2289:… 2254:β 2251:− 2239:∫ 2227:¯ 2035:… 1816:ρ 1750:… 1733:ρ 1730:∫ 1727:… 1724:∫ 1719:∞ 1697:∑ 1693:… 1688:∞ 1666:∑ 1623:… 1603:ρ 1600:∫ 1597:… 1594:∫ 1589:∞ 1567:∑ 1563:… 1558:∞ 1536:∑ 1529:⟩ 1523:⟨ 1264:classical 1204:ψ 1200:⟨ 1197:⟩ 1188:ψ 1163:∑ 1153:^ 1150:ρ 1113:^ 1084:^ 1030:^ 1027:ρ 982:^ 979:ρ 973:⁡ 947:^ 935:^ 896:^ 879:variances 862:^ 827:ρ 821:^ 809:⁡ 800:⟩ 794:⟨ 767:ρ 744:^ 711:^ 708:ρ 660:and from 372:in 1902. 288:Ehrenfest 268:Boltzmann 148:Canonical 4003:Tsallis 3505:(1902). 3399:3-sphere 3301:See also 3050:infinite 2172:ensemble 2165:ensemble 2119:, model 2102:robotics 1938:and the 358:ensemble 283:Einstein 230:Enthalpy 195:Einstein 3998:Shannon 3985:Entropy 3435:measure 2747:removed 2732:sources 2687:is the 2604:is the 1786:density 1334:called 1306:called 646:0 < 564:of the 439:walkers 435:sampled 350:physics 263:Maxwell 3847:Models 3755:Theory 3618:  3565:  3537:  3466:  3232:yes–no 3039:, ..., 2993:itself 2504:where 2182:. The 2151:, the 1893:Since 1862:where 1480:, ... 1464:, ... 1448:, ... 1383:, ... 1367:, ... 1342:, ... 1324:, and 1314:, ... 650:< 1 500:(1903) 366:system 360:(also 298:Tolman 184:Models 4056:chaos 4008:RĂ©nyi 3865:Potts 3860:Ising 3684:(PDF) 3647:arXiv 3421:log 2 3414:log 2 3372:= 1 × 3338:Notes 1293:In a 781:trace 441:in a 356:, an 308:Fermi 303:Debye 278:Gibbs 205:Potts 200:Ising 190:Debye 3938:and 3695:2023 3616:ISSN 3563:ISBN 3535:ISBN 3464:ISBN 3186:Meas 2934:The 2927:and 2730:any 2728:cite 2176:mean 2157:mean 2078:and 1066:and 666:1 − 546:(or 525:(or 513:(or 273:Bose 3657:doi 3608:doi 3140:lim 3067:or 3065:yes 3057:one 3006:gas 2777:In 2741:by 2562:is 2147:In 2088:or 1969:= 1 917:), 877:), 640:If 348:In 169:NPT 161:NPH 153:”VT 145:NVT 137:NVE 4085:: 3811:: 3686:. 3655:. 3643:79 3641:. 3637:. 3614:. 3604:34 3602:. 3478:^ 3419:kT 3264:Tr 3101:, 3090:, 3079:, 3069:no 3032:, 3010:?) 2931:. 2923:, 2703:. 2190:. 2167:. 2139:. 2100:, 1769:1. 1512:: 1473:, 1457:, 1394:. 1376:, 1290:. 1010:. 970:Tr 806:Tr 783:: 633:, 621:, 485:, 481:, 477:, 473:, 424:. 412:. 375:A 3830:G 3825:F 3820:H 3815:U 3740:e 3733:t 3726:v 3697:. 3669:. 3659:: 3649:: 3622:. 3610:: 3571:. 3543:. 3515:. 3472:. 3412:k 3377:h 3370:h 3282:. 3279:) 3276:S 3273:E 3270:( 3261:= 3258:) 3255:E 3252:( 3236:S 3211:) 3206:k 3202:X 3198:, 3195:E 3192:( 3181:N 3176:1 3173:= 3170:k 3160:N 3157:1 3144:N 3136:= 3133:) 3130:E 3127:( 3107:k 3103:X 3099:E 3095:2 3092:X 3088:E 3084:1 3081:X 3077:E 3073:E 3045:k 3041:X 3037:2 3034:X 3030:1 3027:X 2980:V 2976:N 2972:E 2964:N 2960:V 2956:E 2948:N 2944:V 2940:E 2895:. 2885:i 2881:E 2870:e 2864:i 2850:i 2846:E 2835:e 2829:i 2825:A 2819:i 2808:= 2799:A 2768:) 2762:( 2757:) 2753:( 2749:. 2735:. 2701:Z 2672:d 2662:, 2648:i 2644:p 2621:i 2617:q 2602:H 2598:, 2579:T 2576:k 2572:1 2540:, 2538:A 2518:A 2489:, 2479:d 2473:) 2468:N 2464:p 2460:, 2454:, 2449:2 2445:p 2441:, 2436:1 2432:p 2428:, 2423:M 2419:q 2415:, 2409:, 2404:2 2400:q 2396:, 2391:1 2387:q 2383:( 2380:H 2370:e 2356:d 2350:) 2345:N 2341:p 2337:, 2331:, 2326:2 2322:p 2318:, 2313:1 2309:p 2305:, 2300:M 2296:q 2292:, 2286:, 2281:2 2277:q 2273:, 2268:1 2264:q 2260:( 2257:H 2247:e 2243:A 2233:= 2224:A 2051:. 2048:! 2043:s 2039:N 2032:! 2027:2 2023:N 2019:! 2014:1 2010:N 2006:= 2003:C 1985:C 1978:C 1967:C 1961:C 1954:x 1942:. 1931:. 1908:h 1902:h 1896:h 1886:C 1881:. 1878:ρ 1868:h 1847:, 1844:P 1838:C 1833:n 1829:h 1824:1 1819:= 1802:P 1796:ρ 1766:= 1761:n 1757:q 1753:d 1745:1 1741:p 1737:d 1714:0 1711:= 1706:s 1702:N 1683:0 1680:= 1675:1 1671:N 1639:. 1634:n 1630:q 1626:d 1618:1 1614:p 1610:d 1606:X 1584:0 1581:= 1576:s 1572:N 1553:0 1550:= 1545:1 1541:N 1532:= 1526:X 1509:ρ 1503:X 1494:n 1489:) 1486:n 1482:q 1478:1 1475:q 1470:n 1466:p 1462:1 1459:p 1454:s 1450:N 1446:1 1443:N 1441:( 1439:ρ 1430:s 1423:s 1419:N 1413:2 1410:N 1404:1 1401:N 1392:) 1389:n 1385:q 1381:1 1378:q 1373:n 1369:p 1365:1 1362:p 1360:( 1358:ρ 1348:n 1344:p 1340:1 1337:p 1327:n 1320:n 1316:q 1312:1 1309:q 1300:n 1248:i 1244:⟩ 1241:i 1237:ψ 1235:| 1218:, 1214:| 1208:i 1192:i 1183:| 1177:i 1173:P 1167:i 1159:= 1110:N 1081:H 1050:0 1047:= 1044:t 1041:d 1037:/ 1021:d 991:1 988:= 944:Y 932:X 903:2 893:X 859:X 833:. 830:) 818:X 812:( 803:= 797:X 741:X 728:X 671:. 668:p 662:B 658:p 654:A 648:p 642:p 635:B 631:A 623:B 619:A 337:e 330:t 323:v 34:. 20:)

Index

Statistical ensemble (mathematical physics)
Ensemble (disambiguation)
Statistical mechanics

Thermodynamics
Kinetic theory
Particle statistics
Spin–statistics theorem
Indistinguishable particles
Maxwell–Boltzmann
Bose–Einstein
Fermi–Dirac
Parastatistics
Anyonic statistics
Braid statistics
Thermodynamic ensembles
Microcanonical
Canonical
Grand canonical
Isoenthalpic–isobaric
Isothermal–isobaric
Debye
Einstein
Ising
Potts
Potentials
Internal energy
Enthalpy
Helmholtz free energy
Gibbs free energy

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.

↑