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where he became, in 1941, assistant professor, in 1943 associate professor and in 1946 professor. From 1947 to 1950, he was a professor at Purdue
University. From 1950 to 1957, he was a professor at the University of Wisconsin, Madison, and in the academic year 1956/57, the chair of the mathematics
98:
and Max
Schiffer, then at Stanford, improved the Schaeffer–Spencer method and greatly reduced the number of necessary integrations. With this improvement, Garabedian and Schiffer were able in 1955 to prove the conjectured estimate for the fourth coefficient. In 1948, Schaeffer shared the
398:
90:). Their goal was to give a proof for the fourth coefficient, but their approach would have required the numerical integration of about one million
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50:(bachelor's degree 1930) and was, from 1930 to 1933, employed as a highway engineer. In 1936, he received a PhD in mathematics under
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put forward a conjecture in metric diophantine approximation which was resolved in 2020 by
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399:"On the extension of a functional inequality of S. Bernstein to non-analytic functions"
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Schaeffer, Spencer: "Coefficients of schlicht functions", parts I, II, III, IV, in:
561:, American Mathematical Society Colloquium Publications, Vol. 35, Providence, R.I.:
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In 1931, he married
Caroline Juliette Marsh. They had two sons and a daughter.
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210:"Inequalities for harmonic polynomials in two and three dimensions"
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Schaeffer was the son of Albert John and Mary Plane
Schaeffer (
26:– 2 February 1957) was an American mathematician who worked on
638:, vol. 10, 1943, pp. 611–635; vol. 12, 1945, pp. 107–125 and
294:"Some inequalities concerning functions of exponential type"
103:
with
Spencer for their joint work on schlicht functions.
661:"Khinchin's problem in metric Diophantine approximation"
642:, vol. 32, 1946, pp. 111–116; vol. 35, 1949, pp. 143–150
485:"A refinement of the inequality of the brothers Markoff"
444:"Khinchin's problem in metric Diophantine approximation"
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364:"Some properties of functions of exponential type"
74:at Stanford University on variational problems of
712:Koukoulopoulos, Dimitris; Maynard, James (2020).
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250:"Remarks on regularity of methods of summation"
58:. From 1936 to 1939, he was an instructor at
776:Coefficient regions for schlicht functions
558:Coefficient Regions for Schlicht Functions
362:Duffin, Richard; Schaeffer, A. C. (1938).
248:Forsythe, G. E.; Schaeffer, A. C. (1942).
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397:Duffin, R. J.; Schaeffer, A. C. (1940).
327:Schaeffer, A. C.; Duffin, R. J. (1938).
292:Duffin, R. J.; Schaeffer, A. C. (1937).
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778:. By A. C. Schaeffer and D. C. Spencer"
520:"A class of nonharmonic Fourier series"
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78:, for example, coefficient ranges for
62:. In 1939, he became an instructor at
208:Schaeffer, A. C.; Szeg{ö, G. (1941).
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714:"On the Duffin-Schaeffer conjecture"
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614:History of Mathematics at Stanford
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227:10.1090/s0002-9947-1941-0005164-7
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48:University of Wisconsin, Madison
858:People from Belvidere, Illinois
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419:10.1090/s0002-9904-1940-07222-2
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863:Mathematicians from Illinois
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594:Duffin–Schaeffer conjecture
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636:Duke Mathematical Journal
448:Duke Mathematical Journal
167:Schaeffer, A. C. (1941).
131:Schaeffer, A. C. (1937).
816:Albert Charles Schaeffer
20:Albert Charles Schaeffer
619:Who Was Who in America.
138:Trans. Amer. Math. Soc.
116:Dimitris Koukoulopoulos
106:In 1941, Schaeffer and
524:Trans. Amer. Math. Soc
489:Trans. Amer. Math. Soc
214:Trans. Amer. Math. Soc
174:Bull. Amer. Math. Soc.
92:differential equations
70:Schaeffer worked with
16:American mathematician
785:Bull. Amer. Math. Soc
718:Annals of Mathematics
406:Bull. Amer. Math. Soc
368:Bull. Amer. Math. Soc
298:Bull. Amer. Math. Soc
254:Bull. Amer. Math. Soc
125:Selected publications
101:BĂ´cher Memorial Prize
84:Bieberbach conjecture
42:Herrick). He studied
333:Bull. Am. Math. Soc
64:Stanford University
24:Belvidere, Illinois
94:. A little later,
80:schlicht functions
572:978-0-8218-1035-4
76:conformal mapping
60:Purdue University
44:civil engineering
22:(13 August 1907,
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774:"Review:
756:195874052
623:1951–1960
34:Biography
772:(1951).
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588:See also
204:G. Szegő
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