Kevin Ford (mathematician)

Last updated
Kevin B. Ford
Kevin Ford.jpg
Born (1967-12-22) 22 December 1967 (age 56)
NationalityAmerican
Alma mater California State University, Chico
University of Illinois at Urbana-Champaign
Known for
Scientific career
Fields Mathematics
Institutions University of Illinois at Urbana-Champaign
University of South Carolina
Doctoral advisor Heini Halberstam [1]

Kevin B. Ford (born 22 December 1967) is an American mathematician working in analytic number theory.

Contents

Education and career

He has been a professor in the department of mathematics of the University of Illinois at Urbana-Champaign since 2001. Prior to this appointment, he was a faculty member at the University of South Carolina.

Ford received a Bachelor of Science in Computer Science and Mathematics in 1990 from the California State University, Chico. He then attended the University of Illinois at Urbana-Champaign, where he completed his doctoral studies in 1994 under the supervision of Heini Halberstam.

Research

Ford's early work focused on the distribution of Euler's totient function. In 1998, he published a paper that studied in detail the range of this function and established that Carmichael's totient function conjecture is true for all integers up to . [2] In 1999, he settled Sierpinski’s conjecture. [3]

In August 2014, Kevin Ford, in collaboration with Green, Konyagin and Tao, [4] resolved a longstanding conjecture of Erdős on large gaps between primes, also proven independently by James Maynard. [5] The five mathematicians were awarded for their work the largest Erdős prize ($10,000) ever offered. [6] In 2017, they improved their results in a joint paper. [7]

He is one of the namesakes of the Erdős–Tenenbaum–Ford constant, [8] named for his work using it in estimating the number of small integers that have divisors in a given interval. [9]

Recognition

In 2013, he became a fellow of the American Mathematical Society. [10]

Related Research Articles

<span class="mw-page-title-main">Carmichael number</span> Composite number in number theory

In number theory, a Carmichael number is a composite number , which in modular arithmetic satisfies the congruence relation:

A twin prime is a prime number that is either 2 less or 2 more than another prime number—for example, either member of the twin prime pair or (41, 43). In other words, a twin prime is a prime that has a prime gap of two. Sometimes the term twin prime is used for a pair of twin primes; an alternative name for this is prime twin or prime pair.

In number theory, Cramér's conjecture, formulated by the Swedish mathematician Harald Cramér in 1936, is an estimate for the size of gaps between consecutive prime numbers: intuitively, that gaps between consecutive primes are always small, and the conjecture quantifies asymptotically just how small they must be. It states that

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<span class="mw-page-title-main">Ben Green (mathematician)</span> British mathematician

Ben Joseph Green FRS is a British mathematician, specialising in combinatorics and number theory. He is the Waynflete Professor of Pure Mathematics at the University of Oxford.

<span class="mw-page-title-main">Prime gap</span> Difference between two successive prime numbers

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In number theory, the Green–Tao theorem, proved by Ben Green and Terence Tao in 2004, states that the sequence of prime numbers contains arbitrarily long arithmetic progressions. In other words, for every natural number k, there exist arithmetic progressions of primes with k terms. The proof is an extension of Szemerédi's theorem. The problem can be traced back to investigations of Lagrange and Waring from around 1770.

In mathematics, Carmichael's totient function conjecture concerns the multiplicity of values of Euler's totient function φ(n), which counts the number of integers less than and coprime to n. It states that, for every n there is at least one other integer m ≠ n such that φ(m) = φ(n). Robert Carmichael first stated this conjecture in 1907, but as a theorem rather than as a conjecture. However, his proof was faulty, and in 1922, he retracted his claim and stated the conjecture as an open problem.

The Duffin–Schaeffer theorem is a theorem in mathematics, specifically, the Diophantine approximation proposed by R. J. Duffin and A. C. Schaeffer in 1941. It states that if is a real-valued function taking on positive values, then for almost all , the inequality

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<span class="mw-page-title-main">James Maynard (mathematician)</span> British mathematician

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The Erdős–Tenenbaum–Ford constant is a mathematical constant that appears in number theory. Named after mathematicians Paul Erdős, Gérald Tenenbaum, and Kevin Ford, it is defined as

Dimitris Koukoulopoulos is a Greek mathematician working in analytic number theory. He is a professor at the University of Montreal.

References

  1. Kevin Ford at the Mathematics Genealogy Project
  2. Ford, Kevin (1998). "The distribution of totients". Ramanujan Journal. 2 (1–2): 67–151. arXiv: 1104.3264 . doi:10.1023/A:1009761909132. S2CID   6232638.
  3. Ford, Kevin (1999). "The number of solutions of φ(x) = m". Annals of Mathematics. Princeton University and the Institute for Advanced Study. 150 (1): 283–311. doi:10.2307/121103. JSTOR   121103. Archived from the original on 2013-09-24. Retrieved 2019-04-19.
  4. Ford, Kevin; Green, Ben; Konyagin, Sergei; Tao, Terence (2016). "Large gaps between consecutive primes". Annals of Mathematics. 183 (3): 935–974. arXiv: 1408.4505 . doi:10.4007/annals.2016.183.3.4. S2CID   16336889.
  5. Maynard, James (2016). "Large gaps between primes". Annals of Mathematics. Princeton University and the Institute for Advanced Study. 183 (3): 915–933. arXiv: 1408.5110 . doi:10.4007/annals.2016.183.3.3. S2CID   119247836.
  6. Klarreich, Erica (22 December 2014). "Mathematicians Make a Major Discovery About Prime Numbers". Wired. Retrieved 27 July 2015.
  7. Ford, Kevin; Green, Ben; Konyagin, Sergei; Maynard, James; Tao, Terence (2018). "Long gaps between primes". Journal of the American Mathematical Society. 31: 65–105. arXiv: 1412.5029 . doi: 10.1090/jams/876 .
  8. Luca, Florian; Pomerance, Carl (2014). "On the range of Carmichael's universal-exponent function" (PDF). Acta Arithmetica . 162 (3): 289–308. doi:10.4064/aa162-3-6. MR   3173026.
  9. Koukoulopoulos, Dimitris (2010). "Divisors of shifted primes". International Mathematics Research Notices . 2010 (24): 4585–4627. arXiv: 0905.0163 . doi:10.1093/imrn/rnq045. MR   2739805. S2CID   7503281.
  10. List of Fellows of the American Mathematical Society, retrieved 2017-11-03.