In Memoriam

Researchers in this directory who are no longer with us

The Top 100 and the regional pages list living researchers only, so the directory stays accurate for anyone using it to make contact. This page is the one place the directory remembers the 29 figures behind the modern work who have died, 24 of whom also carry a rank in this site's ranked pool.

This is a curated list, not a computed one. Who appears here is an editorial judgement: a person is listed because their work matters to this problem, and every entry is hand-checked. The Rank column shows the site's composite ranked-pool rank for those who carry one, so the quantitative signal stays visible, but it is a guide to the judgement rather than the thing that decides it. A dash means the person is not in the ranked pool at all, which is the normal case for careers that predate the arXiv and OpenAlex record the pipeline reads from. Sort any column; dashes always sort to the bottom.

Contributions

• Luis Báez-Duarte (1938-2018): The Baez-Duarte criterion, a strengthening of the Nyman-Beurling criterion, is standard vocabulary in the Riemann hypothesis literature and appears by name in paper titles
• Paul T. Bateman (1919-2012): The Bateman-Horn conjecture (1962) gives the conjectured density of primes taken simultaneously by several polynomials, the quantitative form of the twin prime and n^2+1 conjectures
• Jean Bourgain (1954-2018): Fields Medalist whose work on exponential sums and the large sieve advanced bounds related to the zeta-function and L-functions
• Nicolaas Govert de Bruijn (1918-2012): The de Bruijn-Newman constant, whose vanishing is equivalent to the Riemann hypothesis, is named after his 1950 work on the zeros of the Fourier transform of the Riemann xi function
• Sarvadaman Chowla (1907-1995): The Chowla-Selberg formula for Epstein zeta values and Chowla's conjecture that Dirichlet L-functions have no real zeros in the critical strip are standard vocabulary in the zeta and L-function literature
• George Csordas (1941-2024): Worked on the Laguerre-Polya class and the Jensen polynomials attached to the Riemann xi function, with Thomas Craven, Wayne Smith and Richard Varga; his complex-zero decreasing sequences are a standard tool in the analytic approach to the Riemann hypothesis
• Harold Davenport (1907-1969): The Davenport constant, the Davenport-Heilbronn theorems and his Multiplicative Number Theory, still a standard reference on primes in progressions and the zeros of L-functions
• Harold M. Edwards (1936-2020): His book Riemann's Zeta Function (1974), with a translation of Riemann's 1859 paper, remains a standard reference on the Riemann hypothesis
• Paul Erdős (1913-1996): The Erdős-Kac theorem, the elementary proof of the prime number theorem with Selberg, and hundreds of problems that shaped probabilistic and additive number theory
• Leonhard Euler (1707-1783): The Euler product joins the zeta function to the primes; Euler's 1742 letters with Goldbach state the conjecture in its modern form
• Patrick X. Gallagher (1935-2019): Gallagher's larger sieve and his theorem that the prime k-tuple conjecture implies Poisson statistics for primes in short intervals are standard tools
• R. R. Hall (1940-2024): Analytic number theorist at York and, with Gerald Tenenbaum, author of "Divisors" (Cambridge, 1988), the standard account of the distribution of divisors and of the Erdos-Hooley Delta function
• G. H. Hardy (1877-1947): With Littlewood, established foundational results on the zeros of the Riemann zeta-function, including infinitely many zeros on the critical line
• A. E. Ingham (1900-1967): His tract The Distribution of Prime Numbers and his work on the zeta-function and the prime number theorem are classics of analytic number theory
• Aleksandar Ivić (1949-2020): Leading analyst on the Riemann zeta function; his book The Riemann Zeta-Function (1985) remains a standard reference
• Borge Jessen (1907-1993): With Wintner, studied the value distribution of the Riemann zeta-function via almost-periodic and probabilistic methods
• Anatoly A. Karatsuba (1937-2008): Major contributions to the theory of the Riemann zeta function and Dirichlet L-functions; founder of a major Russian school
• R. Sherman Lehman (1930-2023): Lehman's 1966 theorem bounding the first sign change of pi(x) - li(x), the basis of later Skewes-number bounds, and his 1970 criterion for verifying zeros of the zeta-function on the critical line; also Lehman's factoring method
• J. E. Littlewood (1885-1977): Long collaboration with Hardy on the zeta-function and the distribution of primes; proved the sign of pi(x) - li(x) changes infinitely often
• Charles-Jean de la Vallée Poussin (1866-1962): Co-proved the Prime Number Theorem (1896) and established the classical zero-free region of the Riemann zeta-function
• Kanakanahalli Ramachandra (1933-2011): Founded the Hardy-Ramanujan Journal; mean value and omega theorems for the Riemann zeta-function, and the six exponentials theorem
• Lowell Schoenfeld (1920-2002): The Rosser-Schoenfeld explicit bounds for prime-counting functions, and Schoenfeld's bound on pi(x) - li(x) under the Riemann hypothesis, are used without explanation
• Atle Selberg (1917-2007): Fields Medalist; the Selberg class and Selberg trace formula are cornerstones of analytic number theory and the spectral approach to RH
• E. C. Titchmarsh (1899-1963): Author of The Theory of the Riemann Zeta-Function, the standard monograph on the subject for generations
• Pál Turán (1910-1976): Created the power-sum (Turan) method and applied it to the zeros of the zeta-function and to comparative prime number theory
• Richard S. Varga (1928-2022): With Csordas and Norfolk proved the Turan inequalities for the Taylor coefficients of the Riemann xi-function, settling a 1927 conjecture of Polya, and led the computational study of the de Bruijn-Newman constant
• Sergei Voronin (1946-1997): Proved the universality theorem for the Riemann zeta-function, showing it approximates any non-vanishing analytic function
• Aurel Wintner (1903-1958): Contributions to analytic number theory and probabilistic number theory bearing on the zeta-function and Dirichlet series
• E. M. Wright (1906-2005): Co-author with Hardy of An Introduction to the Theory of Numbers (1938), the standard reference that number theorists cite simply as Hardy and Wright