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Related papers: Mock Modular Forms and Class Number Relations

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We consider sums of Hurwitz class numbers of the type $\sum_{t \equiv m \pmod{M}}H(4p-t^2)$, where $M$ is composite. For $M=6$ and $8$, we show that these sums can be expressed in terms of coefficients of CM cusp forms. This leads to…

Number Theory · Mathematics 2024-05-14 Mikuláš Zindulka

We define the dimension 2g-1 Faber-Hurwitz Chow/homology classes on the moduli space of curves, parametrizing curves expressible as branched covers of P^1 with given ramification over infinity and sufficiently many fixed ramification points…

Algebraic Geometry · Mathematics 2007-05-23 Ian P. Goulden , David M. Jackson , Ravi Vakil

Recently the author used certain quaternion orders to demonstrate the universality of some quaternary quadratic forms. Here a further study is done on one of these orders analogous to Hurwitz's proof of the formula for the number of…

Number Theory · Mathematics 2007-05-23 Jesse I. Deutsch

By considering the intersections of Shimura curves and Humbert surfaces on the Siegel modular threefold, we obtain new class number relations. The result is a higher-dimensional analogue of the classical Hurwitz-Kronecker class number…

Number Theory · Mathematics 2019-03-19 Jia-Wei Guo , Yifan Yang

We show that Morley's theorem on the number of countable models of a countable first-order theory becomes an undecidable statement when extended to second-order logic. More generally, we calculate the number of equivalence classes of…

Logic · Mathematics 2023-07-06 Christopher J. Eagle , Clovis Hamel , Sandra Müller , Franklin D. Tall

In this paper, we consider sums of class numbers of the type $\sum_{m\equiv a\pmod{p}} H(4n-m^2)$, where $p$ is an odd prime, $n\in \mathbb{N},$ and $a\in \mathbb{Z}$. By showing that these are coefficients of mixed mock modular forms, we…

Number Theory · Mathematics 2019-08-15 Kathrin Bringmann , Ben Kane

Motivated by results for the HCIZ integral in Part I of this paper, we study the structure of monotone Hurwitz numbers, which are a desymmetrized version of classical Hurwitz numbers. We prove a number of results for monotone Hurwitz…

Combinatorics · Mathematics 2011-07-07 Ian P. Goulden , Mathieu Guay-Paquet , Jonathan Novak

Andrews and the third author recently studied congruences for certain restricted two-color partitions. They made two conjectures for Ramanujan-type congruences and a vanishing identity for the limiting sequence. In this paper, we settle…

Number Theory · Mathematics 2026-04-03 Koustav Banerjee , Kathrin Bringmann , Mohamed El Bachraoui

We extend the relation between quasi-modular forms and modular forms to a wider class of functions. We then relate both forms to vector-valued modular forms with symmetric power representations, and prove a general structure theorem for…

Number Theory · Mathematics 2020-08-12 Shaul Zemel

In this paper, the generating functions of Garvans so-called $k$-ranks are used, to define a family of mock Eisenstein series. The $k$-rank moments are then expressed as partition traces of these functions. We explore the modular properties…

Number Theory · Mathematics 2025-10-07 Kilian Rausch

Hurwitz spaces are moduli of isotopy classes of covers. A specific space is formed from a finite group G and C, r of its conjugacy classes and an equivalence relation \dagger. Components, interpret as a braid orbits on Nielsen classes.…

Algebraic Geometry · Mathematics 2025-09-12 Michael D. Fried

Using the method of multiple Dirichlet series, we develop L-functions ratios conjecture with one shift in both the numerator and denominator in certain ranges for quadratic families of Dirichlet and Hecke L-functions of primerelated moduli…

Number Theory · Mathematics 2024-04-11 Peng Gao , Liangyi Zhao

Let Z(X) be the number of degree-d extensions of F_q(t) with bounded discriminant and some specified Galois group. The problem of computing Z(X) can be related to a problem of counting F_q-rational points on certain Hurwitz spaces.…

Number Theory · Mathematics 2008-09-16 Seyfi Turkelli

In [5] I.P. Goulden, D.M. Jackson, and R. Vakil formulated a conjecture relating certain Hurwitz numbers (enumerating ramified coverings of the sphere) to the intersection theory on a conjectural Picard variety. We are going to use their…

Algebraic Geometry · Mathematics 2018-07-18 Sergey Shadrin , Dimitri Zvonkine

Utilizing a classification due to Lemke Oliver of eta-quotients which are also theta functions (here called eta-theta functions), Folsom, Garthwaite, Kang, Treneer, and the fourth author constructed a catalog of mock modular forms $V_{mn}$…

Number Theory · Mathematics 2019-09-20 Allison Arnold-Roksandich , Brian Diaz , Erin Ellefsen , Holly Swisher

We discuss two simple but useful observations that allow the construction of modular forms from given ones using invariant theory. The first one deals with elliptic modular forms and their derivatives, and generalizes the Rankin-Cohen…

Number Theory · Mathematics 2023-04-10 Fabien Cléry , Gerard van der Geer

The modular representation theory of finite groups has its origins in the work of Richard Brauer. In this survey article we first discuss the work being done on some outstanding conjectures in the theory. We then describe work done in the…

Representation Theory · Mathematics 2011-08-17 Bhama Srinivasan

The asymptotic study of class numbers of binary quadratic forms is a foundational problem in arithmetic statistics. Here, we investigate finer statistics of class numbers by studying their self-correlations under additive shifts.…

Number Theory · Mathematics 2025-10-22 Alexander Walker

By the theory of Eisenstein series, generating functions of various divisor functions arise as modular forms. It is natural to ask whether further divisor functions arise systematically in the theory of mock modular forms. We establish,…

Number Theory · Mathematics 2020-09-30 Michael H. Mertens , Ken Ono , Larry Rolen

In this work, we prove that many Ap\'ery-like sequences arising from modular forms satisfy the Lucas congruences modulo any prime. As an implication, we completely affirm four conjectural Lucas congruences that were recently posed by S.…

Number Theory · Mathematics 2024-10-24 Frits Beukers , Wei-Lun Tsai , Dongxi Ye