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Haseo Ki

Yonsei University · Mathematics

About the Lab

Professor Haseo Ki's research spans analytic number theory, with a focus on the distribution of zeros of zeta and L-functions, including the Riemann zeta function, Epstein zeta functions, and Weng’s zeta functions for algebraic groups. His work delves into the spectral properties of these functions, particularly the location, density, and simplicity of nontrivial zeros, often under the assumption or implication of the Riemann Hypothesis. He also investigates functional equations, special functions, and connections to transcendental number theory and Diophantine approximation.

zeta functionsRiemann Hypothesiszero densityanalytic number theoryL-functions

Research Overview

Papers
46
Total Citations
338
Papers (5y)
6
Primary Field
Mathematics

Research Output Trend

Figures are computed from collected data and may differ slightly.

Publications per year (5y)
6total
2014
2016
2017
2021
2023
Citations per year (5y)
17total
20142016201720212023

Selected Papers

15
1
Article|48 citations·2000
On the number of nonreal zeros of real entire functions and the Fourier-Pólya conjecture
Haseo Ki, Young-One Kim
SJR Q1Duke Mathematical Journal

This paper is concerned with a general theorem on the number of nonreal zeros of transcendental functions. J. Fourier formulated the theorem in his work Analyse des equations determineesin 1831, but he did not give a proof. Roughly speaking, the theorem states that if a real entire function f( x)can be expressed as a product of linear factors, then we can count the nonreal zeros of f( x)by observing the behavior of the derivatives of f( x)on the real axis alone. As we shall see in the sequel, th

Applied MathematicsMathematics
2
Article|30 citations·1994
Normal numbers and subsets of N with given densities
Haseo Ki, Том Линтон
SJR Q2Fundamenta MathematicaeOA

For X ⊆ [0,1], let $D_X$ denote the collection of subsets of ℕ whose densities lie in X. Given the exact location of X in the Borel or difference hierarchy, we exhibit the exact location of $D_X$. For α ≥ 3, X is properly $D_ξ(Π^0_α)$ iff $D_X$ is properl

Numerical AnalysisMathematics
3
Article|23 citations·2009
On the de Bruijn–Newman constant
Haseo Ki, Young-One Kim, Jungseob Lee
SJR Q1Advances in Mathematics
Algebra and Number TheoryMathematics
4
Article|16 citations·2005
All but finitely many non-trivial zeros of the approximations of the Epstein zeta function are simple and on the critical line
Haseo Ki
SJR Q1Proceedings of the London Mathematical Society

The Chowla–Selberg formula is applied in approximating a given Epstein zeta function. Partial sums of the series derive from the Chowla–Selberg formula, and although these partial sums satisfy a functional equation, as does an Epstein zeta function, they do not possess an Euler product. What we call partial sums throughout this paper may be considered as special cases concerning a more general function satisfying a functional equation only. In this article we study the distribution of zeros of t

Algebra and Number TheoryMathematics
5
Article|13 citations·2012
A remark on the uniqueness of the Dirichlet series with a Riemann-type function equation
Haseo Ki
SJR Q1Advances in Mathematics
Mathematical PhysicsMathematics
6
Article|12 citations·2006
Zeros of the constant term in the Chowla–Selberg formula
Haseo Ki
SJR Q2Acta ArithmeticaOA
Algebra and Number TheoryMathematics
7
Article|11 citations·2008
The Zeros of the Derivative of the Riemann Zeta Function Near the Critical Line
Haseo Ki
SJR Q1International Mathematics Research Notices

We study the horizontal distribution of zeros of ζ′(s) which are denoted as ρ′ =β′ +iγ′. We assume the Riemann hypothesis which implies β′ ≥ 1/2 for any nonreal zero ρ′, equality being possible only at a multiple zero of ζ (s). In this paper, we prove that lim inf (β′ −1/2)log γ′ ≠ 0 if, and only if, for any c > 0 and s = σ + <it>it</it> with 0 ≤|σ -1/2| ≤c/log t (t>t<inf>0</inf>(c)), we have<fd id="M1"><inline-fig> <link locator="rnn064ueq1"></

Algebra and Number TheoryMathematics
8
Article|11 citations·2003
De Bruijn’s question on the zeros of Fourier transforms
Haseo Ki, Young-One Kim
SJR Q1Journal d Analyse Mathématique
Applied MathematicsMathematics
9
Article|11 citations·2014
A uniqueness theorem for functions in the extended Selberg class
S. M. Gonek, Jaeho Haan, Haseo Ki
SJR Q1Mathematische Zeitschrift
Applied MathematicsMathematics
10
Article|11 citations·2012
Landau–Siegel zeros and zeros of the derivative of the Riemann zeta function
David W. Farmer, Haseo Ki
SJR Q1Advances in Mathematics
Algebra and Number TheoryMathematics
11
Article|10 citations·2005
The Riemann Ξ-function under repeated differentiation
Haseo Ki
SJR Q2Journal of Number Theory
Applied MathematicsMathematics
12
Article|10 citations·2004
On a theorem of Levinson
Haseo Ki
SJR Q2Journal of Number Theory
Theoretical Computer ScienceMathematics
13
Article|9 citations·2012
Zeros of the derivatives of the Riemann zeta-function
Haseo Ki, Yoonbok Lee
SJR Q3Functiones et Approximatio Commentarii Mathematici

Levinson and Montgomery in 1974 proved many interesting formulae on the zeros of derivatives of the Riemann zeta function $\zeta(s)$. When Conrey proved that at least 2/5 of the zeros of the Riemann zeta function are on the critical line, he proved the asymptotic formula for the mean square of $\zeta(s)$ multiplied by a mollifier of length $ T^{4/7}$ near the $1/2$-line. As a consequence of their papers, we study some aspects of zeros of the derivatives of the Riemann zeta function with no assum

Algebra and Number TheoryMathematics
14
Article|8 citations·2000
On the Zeros of Some Generalized Hypergeometric Functions
Haseo Ki, Young-One Kim
SJR Q1Journal of Mathematical Analysis and Applications
Numerical AnalysisMathematics
15
Article|7 citations·2007
On the zeros of approximations of the Ramanujan Ξ-function
Haseo Ki
SJR Q2The Ramanujan Journal
Algebra and Number TheoryMathematics

Research Areas

Algebra and Number TheoryApplied MathematicsNumerical AnalysisGeometry and TopologyMathematical PhysicsTheoretical Computer Science

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