Knowledge

Schwarz reflection principle

Source 📝

154: 235: 301: 334:
clearly split into two, using part of the real axis. So, given that the principle is rather easy to prove in the special case from Morera's theorem, understanding the proof is enough to generate other results.
146: 77: 178: 244: 86: 449: 454: 19:
This article is about the reflection principle in complex analysis. For reflection principles of set theory, see
400: 410: 444: 405: 35: 153: 356: 420: 304: 50:, then it can be extended to the conjugate function on the lower half-plane. In notation, if 39: 319: 238: 79:
is a function that satisfies the above requirements, then its extension to the rest of the
20: 53: 8: 323: 303:, which takes real values on the real axis. Then the extension formula given above is an 172: 322:. To understand such extensions, one needs a proof method that can be weakened. In fact 339: 361: 351: 327: 43: 230:{\displaystyle \left\{z\in \mathbb {C} \mid \operatorname {Im} (z)\geq 0\right\}} 164: 157: 296:{\displaystyle \left\{z\in \mathbb {C} \mid \operatorname {Im} (z)>0\right\}} 438: 80: 27: 425: 417: 47: 383:
Elementary theory of analytic functions of one or several variables
150:
That is, we make the definition that agrees along the real axis.
310:
In practice it would be better to have a theorem that allows
42:. It states that if an analytic function is defined on the 46:, and has well-defined (non-singular) real values on the 247: 181: 89: 56: 295: 229: 140: 71: 141:{\displaystyle F({\bar {z}})={\overline {F(z)}}.} 34:is a way to extend the domain of definition of a 436: 326:is well adapted to proving such statements. 260: 194: 16:Mathematics principle in complex analysis 152: 437: 338:The principle also adapts to apply to 418: 314:certain singularities, for example 13: 380: 14: 466: 393: 175:on the closed upper half plane 421:"Schwarz reflection principle" 374: 279: 273: 213: 207: 126: 120: 108: 102: 93: 66: 60: 1: 367: 450:Theorems in complex analysis 307:to the whole complex plane. 167:is as follows. Suppose that 130: 32:Schwarz reflection principle 7: 406:Encyclopedia of Mathematics 401:"Riemann-Schwarz principle" 345: 330:involving the extension of 10: 471: 18: 83:is given by the formula, 36:complex analytic function 241:on the upper half plane 38:, i.e., it is a form of 455:Mathematical principles 357:Method of image charges 297: 231: 160: 142: 73: 305:analytic continuation 298: 232: 163:The result proved by 156: 143: 74: 40:analytic continuation 320:meromorphic function 245: 179: 87: 72:{\displaystyle F(z)} 54: 21:Reflection principle 173:continuous function 445:Harmonic functions 340:harmonic functions 293: 227: 161: 138: 69: 328:Contour integrals 133: 105: 462: 431: 430: 414: 387: 386: 378: 362:Schwarz function 352:Kelvin transform 324:Morera's theorem 302: 300: 299: 294: 292: 288: 263: 236: 234: 233: 228: 226: 222: 197: 147: 145: 144: 139: 134: 129: 115: 107: 106: 98: 78: 76: 75: 70: 44:upper half-plane 470: 469: 465: 464: 463: 461: 460: 459: 435: 434: 399: 396: 391: 390: 381:Cartan, Henri. 379: 375: 370: 348: 259: 252: 248: 246: 243: 242: 193: 186: 182: 180: 177: 176: 165:Hermann Schwarz 158:Hermann Schwarz 116: 114: 97: 96: 88: 85: 84: 55: 52: 51: 24: 17: 12: 11: 5: 468: 458: 457: 452: 447: 433: 432: 419:Todd Rowland. 415: 395: 394:External links 392: 389: 388: 372: 371: 369: 366: 365: 364: 359: 354: 347: 344: 291: 287: 284: 281: 278: 275: 272: 269: 266: 262: 258: 255: 251: 225: 221: 218: 215: 212: 209: 206: 203: 200: 196: 192: 189: 185: 137: 132: 128: 125: 122: 119: 113: 110: 104: 101: 95: 92: 68: 65: 62: 59: 15: 9: 6: 4: 3: 2: 467: 456: 453: 451: 448: 446: 443: 442: 440: 428: 427: 422: 416: 412: 408: 407: 402: 398: 397: 385:. p. 75. 384: 377: 373: 363: 360: 358: 355: 353: 350: 349: 343: 341: 336: 333: 329: 325: 321: 317: 313: 308: 306: 289: 285: 282: 276: 270: 267: 264: 256: 253: 249: 240: 223: 219: 216: 210: 204: 201: 198: 190: 187: 183: 174: 170: 166: 159: 155: 151: 148: 135: 123: 117: 111: 99: 90: 82: 81:complex plane 63: 57: 49: 45: 41: 37: 33: 29: 22: 424: 404: 382: 376: 337: 331: 315: 311: 309: 168: 162: 149: 31: 25: 239:holomorphic 28:mathematics 439:Categories 368:References 426:MathWorld 411:EMS Press 271:⁡ 265:∣ 257:∈ 217:≥ 205:⁡ 199:∣ 191:∈ 131:¯ 103:¯ 48:real axis 346:See also 413:, 2001 30:, the 171:is a 283:> 26:In 441:: 423:. 409:, 403:, 342:. 318:a 268:Im 237:, 202:Im 429:. 332:F 316:F 312:F 290:} 286:0 280:) 277:z 274:( 261:C 254:z 250:{ 224:} 220:0 214:) 211:z 208:( 195:C 188:z 184:{ 169:F 136:. 127:) 124:z 121:( 118:F 112:= 109:) 100:z 94:( 91:F 67:) 64:z 61:( 58:F 23:.

Index

Reflection principle
mathematics
complex analytic function
analytic continuation
upper half-plane
real axis
complex plane

Hermann Schwarz
Hermann Schwarz
continuous function
holomorphic
analytic continuation
meromorphic function
Morera's theorem
Contour integrals
harmonic functions
Kelvin transform
Method of image charges
Schwarz function
"Riemann-Schwarz principle"
Encyclopedia of Mathematics
EMS Press
"Schwarz reflection principle"
MathWorld
Categories
Harmonic functions
Theorems in complex analysis
Mathematical principles

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