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Related papers: Modular forms for the $A_{1}$-tower

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Let L >= 3. Using the moduli interpretation, we define certain elliptic modular forms of level Gamma(L) over any field k where 6L is invertible and k contains the Lth roots of unity. These forms generate a graded algebra R_L, which, over C,…

Number Theory · Mathematics 2012-04-09 Kamal Khuri-Makdisi

We investigate explicit modular forms of weights $1/2$ and $3/2$-classical, minus, and fermionic theta series-arising from the classical Weil representation associated to $\operatorname{SL}_2(\mathbb{R})$ via the $2$-cocycles of Rao, Kudla,…

Number Theory · Mathematics 2026-05-22 Chun-Hui Wang

We introduce and study higher depth quantum modular forms. We construct two families of examples coming from rank two false theta functions, whose "companions" in the lower half-plane can be also realized both as double Eichler integrals…

Number Theory · Mathematics 2018-03-19 Kathrin Bringmann , Jonas Kaszian , Antun Milas

In this paper, we study wall elements of rank 2 cluster scattering diagrams based on dilogarithm elements. We derive two major results. First, we give a method to calculate wall elements in lower degrees. By this method, we may see the…

Combinatorics · Mathematics 2024-01-10 Ryota Akagi

We give generators and relations for the graded rings of Hermitian modular forms of degree two over the rings of integers in $\mathbb{Q}(\sqrt{-7})$ and $\mathbb{Q}(\sqrt{-11})$. In both cases we prove that the subrings of symmetric modular…

Number Theory · Mathematics 2020-01-14 Brandon Williams

In 2000, based on his procedure for constructing explicit towers of modular curves, Elkies deduced explicit equations of rank-2 Drinfeld modular curves which coincide with the asymptotically optimal towers of curves constructed by Garcia…

Number Theory · Mathematics 2020-05-05 Rui Chen , Zhuo Chen , Chuangqiang Hu

In this paper, we study Siegel modular forms with extra twists. We provide conditions on the level and genus of the forms that is necessary for the existence of extra twists for Siegel modular forms. We also give explicit examples of Siegel…

Number Theory · Mathematics 2023-11-07 Debargha Banerjee , Ronit Debnath

There are a variety of characterizations of Saito-Kurokawa lifts from elliptic modular forms to Siegel modular forms of degree 2. In addition to giving a survey of known characterizations, we apply a recent result of Weissauer to provide a…

Number Theory · Mathematics 2013-06-04 David W. Farmer , Ameya Pitale , Nathan C. Ryan , Ralf Schmidt

Let $k$ be a perfect field with $\mathrm{char}(k)\neq 2,3$, set $K=k(t)$, and let $\mathcal{W}_n^{\min}$ be the moduli stack of minimal elliptic curves over $K$ of Faltings height $n$, constructed via the height-moduli framework of…

Algebraic Geometry · Mathematics 2026-05-01 Jun-Yong Park

We design efficient algorithms to evaluate modular equations of Siegel and Hilbert type for abelian surfaces over number fields or finite fields using complex approximations. Their output is provably correct when the associated graded ring…

Number Theory · Mathematics 2025-01-17 Jean Kieffer

In this paper we investigate the (classical) weights of mod $p$ Siegel modular forms of degree 2 toward studying Serre's conjecture for $GSp_4$. We first construct various theta operators on the space of such forms a la Katz and define the…

Number Theory · Mathematics 2022-10-19 Takuya Yamauchi

We describe the construction of vector valued modular forms transforming under a given congruence representation of the modular group SL$(\bold Z)$ in terms of theta series. We apply this general setup to obtain closed and easily computable…

Number Theory · Mathematics 2009-10-28 Wolgang Eholzer , Nils-Peter Skoruppa

We construct almost holomorphic and holomorphic modular forms by considering theta series for quadratic forms of signature $(n-1,1)$. We include homogeneous and spherical polynomials in the definition of the theta series (generalizing a…

Number Theory · Mathematics 2021-02-19 Christina Roehrig , Sander Zwegers

We describe a new link between the theory of topological modular forms and representations of vertex operator algebras obtained by certain lattices. The construction is motivated by the arithmetic Whitehead tower of the orthogonal groups.…

Algebraic Topology · Mathematics 2021-10-18 Nora Ganter , Gerd Laures

In this paper we prove two results concerning the classification of Siegel modular threefolds. Let A_{1,d}(n) be the moduli space of abelian surfaces with a (1,d)-polarization and a full level-n structure and let A_{1,d}^{lev}(n) be the…

Algebraic Geometry · Mathematics 2007-05-23 Klaus Hulek

Given a weight 2 and level p^2 modular form f, we construct two weight 3/2 modular forms (possibly zero) of level 4p^2 and non trivial character mapping to f via the Shimura correspondence. Then we relate the coefficients of the constructed…

Number Theory · Mathematics 2021-07-14 Ariel Pacetti , Gonzalo Tornaría

We study the cohomology of certain local systems on moduli spaces of principally polarized abelian surfaces with a level 2 structure. The trace of Frobenius on the alternating sum of the \'etale cohomology groups of these local systems can…

Algebraic Geometry · Mathematics 2008-04-20 Jonas Bergström , Carel Faber , Gerard van der Geer

In this article, a large class of simple modules over the Schr\"odinger-Virasoro algebra $\mathcal{G}$ are constructed, which include highest weight modules and Whittaker modules. These modules are determined by the simple modules over the…

Representation Theory · Mathematics 2016-08-30 Haibo Chen , Yanyong Hong , Yucai Su

We investigate the existence and non-existence of modular forms of low weight with a character with respect to the paramodular group $\Gamma_t$ and discuss the resulting geometric consequences. Using an advanced version of Maa\ss\ lifting…

alg-geom · Mathematics 2008-02-03 V. Gritsenko , K. Hulek

The explicit construction of function fields tower with many rational points relative to the genus in the tower play a key role for the construction of asymptotically good algebraic-geometric codes. In 1997 Garcia, Stichtenoth and Thomas…

Number Theory · Mathematics 2007-09-21 Siman Yang