Tom Brown (mathematician)

Thomas Craig Brown (born 1938) is an American-Canadian mathematician, Ramsey Theorist, and Professor Emeritus at Simon Fraser University.[1]

Tom Brown
Born
Thomas Craig Brown

1938 (age 85–86)
Alma mater
Known for
  • Brown's Lemma
Scientific career
Fields
InstitutionsSimon Fraser University
Thesis On Semigroups which are Unions of Periodic Groups  (1964)
Doctoral advisorEarl Edwin Lazerson

Collaborations edit

As a mathematician, Brown’s primary focus in his research is in the field of Ramsey Theory. When completing his Ph.D., his thesis was 'On Semigroups which are Unions of Periodic Groups'[2] In 1963 as a graduate student, he showed that if the positive integers are finitely colored, then some color class is piece-wise syndetic.[3]

In A Density Version of a Geometric Ramsey Theorem.[4] he and Joe P. Buhler show that “for every   there is an   such that if   then any subset of   with more than   elements must contain 3 collinear points” where   is an  -dimensional affine space over the field with   elements, and  ".

In Descriptions of the characteristic sequence of an irrational,[5] Brown discusses the following idea: Let   be a positive irrational real number. The characteristic sequence of   is  ; where  .” From here he discusses “the various descriptions of the characteristic sequence of α which have appeared in the literature” and refines this description to “obtain a very simple derivation of an arithmetic expression for  .” He then gives some conclusions regarding the conditions for   which are equivalent to  .

He has collaborated with Paul Erdős, including Quasi-Progressions and Descending Waves[6] and Quantitative Forms of a Theorem of Hilbert.[7]

References edit

  1. ^ "Tom Brown Professor Emeritus at SFU". Retrieved 10 November 2020.
  2. ^ Jensen, Gary R.; Krantz, Steven G. (2006). 150 Years of Mathematics at Washington University in St. Louis. American Mathematical Society. p. 15. ISBN 978-0-8218-3603-3.
  3. ^ Brown, T. C. (1971). "An interesting combinatorial method in the theory of locally finite semigroups" (PDF). Pacific Journal of Mathematics. 36 (2): 285–289. doi:10.2140/pjm.1971.36.285.
  4. ^ Brown, T. C.; Buhler, J. P. (1982). "A Density version of a Geometric Ramsey Theorem" (PDF). Journal of Combinatorial Theory. Series A. 32: 20–34. doi:10.1016/0097-3165(82)90062-0.
  5. ^ Brown, T. C. (1993). "Descriptions of the Characteristic Sequence of an Irrational" (PDF). Canadian Mathematical Bulletin. 36: 15–21. doi:10.4153/CMB-1993-003-6.
  6. ^ Brown, T. C.; Erdős, P.; Freedman, A. R. (1990). "Quasi-Progressions and Descending Waves". Journal of Combinatorial Theory. Series A. 53: 81–95. doi:10.1016/0097-3165(90)90021-N.
  7. ^ Brown, T. C.; Chung, F. R. K.; Erdős, P. (1985). "Quantitative Forms of a Theorem of Hilbert" (PDF). Journal of Combinatorial Theory. Series A. 38 (2): 210–216. doi:10.1016/0097-3165(85)90071-8.

External links edit