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Related papers: Borcherds Products on Unitary Group $U(2,1)$

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In this note, we describe several new examples of holomorphic modular forms on the group SU(2,1). These forms are distinguished by having weight $\frac{1}{3}$. We also describe a method for determining the levels at which one should expect…

Number Theory · Mathematics 2022-03-03 Eberhard Freitag , Richard M. Hill

We develop a new algorithm to compute a basis for $M_k(\Gamma_0(N))$, the space of weight $k$ holomorphic modular forms on $\Gamma_0(N)$, in the case when the graded algebra of modular forms over $\Gamma_0(N)$ is generated at weight two.…

Number Theory · Mathematics 2017-09-25 Michael Lam , Noah McClelland , Matthew Petty , John Webb

For any $m \ge 1$ and odd prime power $\mathtt{q}=\mathtt{p}^m$, for $\mathtt{q}=2$, and for any $n \ge 1$, we show a result of decomposition for Pauli groups $\mathcal{P}_{n,\mathtt{q}}$ in terms of weak central products. This can be used…

Group Theory · Mathematics 2020-09-09 Andrea Rocchetto , Francesco G. Russo

We develop a theory of weights for a quantum analogue of the symmetric pair (gl4,gl2 x gl2) realised as a quantum symmetric pair subalgebra. Based on Letzter's triangular decomposition we define Verma modules. Using magical operators that…

Representation Theory · Mathematics 2026-01-27 Catharina Stroppel , Liao Wang

We introduce the $L$-series of weakly holomorphic modular forms using Laplace transforms and give their functional equations. We then determine converse theorems for vector-valued harmonic weak Maass forms, Jacobi forms, and elliptic…

Number Theory · Mathematics 2025-01-29 Subong Lim , Wissam Raji

Quasi-pullback of Borcherds products is an operation of renormalized restriction. It produces a meromorphic modular form on a lower dimensional symmetric domain which is again a Borcherds product. We give an explicit formula for the weakly…

Number Theory · Mathematics 2019-10-14 Shouhei Ma

We construct an integral form for the universal enveloping algebra of the Onsager algebra and an explicit integral basis for this integral form. We also formulate straightening identities among some products of basis elements.

Rings and Algebras · Mathematics 2020-06-22 Angelo Bianchi , Samuel Chamberlin

We study the finite dimensional modules on the half-quantum group u_q^+ at a root of unity q, whose action can be extended to u_q (quotient of the quantized enveloping algebra of sl_2). We derive decomposition formulas of the tensor product…

Quantum Algebra · Mathematics 2007-05-23 Elisabet Gunnlaugsdottir

We prove a bound for the Fourier coefficients of a cusp form of integral weight which is not a newform by computing an explicit orthogonal basis for the space of cusp forms of given integral weight and level. In contrast to previous work on…

Number Theory · Mathematics 2018-08-27 Rainer Schulze-Pillot , Abdullah Yenirce

We apply Zagier's result for the traces of singular moduli to construct Borcherds products in higher level cases.

Number Theory · Mathematics 2007-05-23 Chang Heon Kim

In this paper we generalise the notion of Drinfeld modular form for the group $\Gamma$ := GL2(Fq[$\theta$]) to a vector-valued setting, where the target spaces are certain modules over positive characteristic Banach algebras over which are…

Number Theory · Mathematics 2021-07-14 Federico Pellarin

We show that the modular branching rule (in the sense of Harish-Chandra) on unipotent modules for finite unitary groups is piecewise described by particular connected components of the crystal graph of well-chosen Fock spaces, under…

Representation Theory · Mathematics 2015-02-09 Thomas Gerber , Gerhard Hiss

We establish a new converse theorem for Borcherds products. Moreover, the injectivity of the Kudla-Millson theta lift is demonstrated in the O$(n,2)$ case in greater generality than is currently available in the literature. Both results are…

Number Theory · Mathematics 2025-12-25 Ingmar Metzler

We study the existence of unitriangular basic sets for the symmetric group which behave nicely with respect to the Mullineux involution. Such sets give a natural labelling for the modular irreducible representations. We show that, for any…

Combinatorics · Mathematics 2021-11-23 Ana Bernal

We show that the values of a certain family of weakly holomorphic modular functions at points in the divisors of any meromorphic modular form with algebraic Fourier coefficients are algebraic. We use this to extend the classical result of…

Number Theory · Mathematics 2021-07-05 Daeyeol Jeon , Soon-Yi Kang , Chang Heon Kim

We associate to a bound quiver (Q,I) a CW-complex which we denote by B(Q,I), and call the classifying space of (Q,I). We show that the fundamental group of B(Q,I) is isomorphic to the fundamental group of (Q,I). Moreover, we show that this…

Representation Theory · Mathematics 2007-05-23 J. C. Bustamante

We study the modular representation theory of the symmetric and alternating groups. One of the most natural ways to label the irreducible representations of a given group or algebra in the modular case is to show the unitriangularity of the…

Representation Theory · Mathematics 2020-12-09 Olivier Brunat , Jean-Baptiste Gramain , Nicolas Jacon

Let $\Gamma_{F,n}$ be the Hermitian modular group of degree $n>1$ in sense of Hel Braun with respect to an imaginary quadratic field $F$. Let $r$ be a natural number. There exists a multiplier system of weight $1/r$ (equivalently a…

Number Theory · Mathematics 2020-11-10 Eberhard Freitag

In the first part of this article, which contains three of them, we have identified the notion of level $N$ strong modular unit. It enabled us to structure the modular forms family $(M_{2k}(\Gamma_0(N)))_{k\in \mathbb{N}^*}$ and to propose…

Number Theory · Mathematics 2018-09-05 Jean-Christophe Feauveau

In this paper, we construct a novel class of simple modules for the $W$-algebra $W(2,2)$. Our approach involves taking tensor products of finitely many non-weight simple modules $\Omega(\lambda,\alpha,h)$ with an arbitrary simple restricted…

Representation Theory · Mathematics 2025-06-11 Hongjia Chen , Dashu Xu