activity
20032026
most citedCounting Cubic Extensions with given Quadratic Resolvent

23 citations · 57 across the 17 of their papers we have counts for

collaborators

19 papers

math.NT2026

The Shimura Lift and Hilbert Modular Forms

Henri Cohen

After recalling basic formulas concerning modular forms of half-integral weight, Gegenbauer polynomials, and Rankin--Cohen brackets, we give four versions of the Shimura lift and s…

math.NT2026

On the Argument of the Lerch, Chowla--Selberg Formula and CM Values of

Henri Cohen

We give a completely explicit Lerch, Chowla--Selberg formula without absolute values of the Dedekind eta function, and give some applications, in particular to the argument of indi…

math.NT2023

Parametric Continued Fractions for , , and other Constants

Henri Cohen

We give an extensive list of parametrized families of polynomial continued fractions of smallest possible degrees for and , and mention similar results for other consta…

math.NT2022

Elementary Continued Fractions for Linear Combinations of Zeta and L Values

Henri Cohen

We show how to obtain infinitely many continued fractions for certain Z-linear combinations of zeta and L values. The methods are completely elementary.

math.NT2021

Factorizations of Eisenstein Series of Level up to 4

Henri Cohen

We show that the most standard Eisenstein series such as or , and also the function , are in a natural way the product of two conjugate Eisenstein…

math.NT2021★ 1 cited

Rational Hypergeometric Ramanujan Identities for : Survey and Generalizations

Henri Cohen, Jesús Guillera

We give a simple unified proof for all existing rational hypergeometric Ramanujan identities for , and give a complete survey (without proof) of several generalizations: ratio…

math.NT2021

Computing L-Functions of Quadratic Characters at Negative Integers

Henri Cohen

We survey a number of different methods for computing for a Dirichlet character , with particular emphasis on quadratic characters. The main conclusion is that when $…

math.CV2021

Lambert -Function Branch Identities

Henri Cohen

After defining in detail the Lambert -function branches, we give a large number of exact identities involving (infinite) symmetric functions of these branches, as well as geomet…

math.NT2018

Modular Forms in Pari/GP

Karim Belabas, Henri Cohen

We give theoretical and practical information on the Pari/GP modular forms package available since the spring of 2018. Thanks to the use of products of two Eisenstein series, this…

math.NT2018

Expansions at Cusps and Petersson Products in Pari/GP

Henri Cohen

We begin by explaining how to compute Fourier expansions at all cusps of any modular form of integral or half-integral weight thanks to a theorem of Borisov-Gunnells and explicit e…

math.NT2018

An Introduction to Modular Forms

Henri Cohen

In this course we introduce the main notions relative to the classical theory of modular forms. A complete treatise in a similar style can be found in the author's book joint with…

math.NT2018

Computational Number Theory in Relation with L-Functions

Henri Cohen

We give a number of theoretical and practical methods related to the computation of L-functions, both in the local case (counting points on varieties over finite fields, involving…

math.NT2016★ 7 cited

On -extensions of odd prime degree

Henri Cohen, Frank Thorne

Generalizing the work of A. Morra and the authors, we give explicit formulas for the Dirichlet series generating function of -extensions of odd prime degree with g…

math.NT2015

Finite hypergeometric functions

Frits Beukers, Henri Cohen, Anton Mellit

Finite hypergeometric functions are complex valued functions on finite fields which are the analogue of the classical analytic hypergeometric functions. From the work of N.M.Katz i…

math.NT2013

Dirichlet series associated to cubic fields with given quadratic resolvent

Henri Cohen, Frank Thorne

Let k be a quadratic field. We give an explicit formula for the Dirichlet series enumerating cubic fields whose quadratic resolvent field is isomorphic to k. Our work is a sequel t…

math.NT2010★ 23 cited

Counting Cubic Extensions with given Quadratic Resolvent

Henri Cohen, Anna Morra

Given a number field and a quadratic extension , we give an explicit asymptotic formula for the number of isomorphism classes of cubic extensions of whose Galois closu…

math.NT2009★ 22 cited

Elementary 3-descent with a 3-isogeny

Henri Cohen, Fabien Pazuki

In this expository paper, we show how to use in practice 3-descent with a 3-isogeny to find an estimate for the rank of an elliptic curve having a rational 3-torsion subgroup, and…

math.NT2008★ 2 cited

Computational class field theory

Henri Cohen, Peter Stevenhagen

Class field theory furnishes an intrinsic description of the abelian extensions of a number field that is in many cases not of an immediate algorithmic nature. We outline the algor…

math.NT2003★ 2 cited

Constructing and counting number fields

Henri Cohen

In this paper we give a survey of recent methods for the asymptotic and exact enumeration of number fields with given Galois group of the Galois closure. In particular, the case of…