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Related papers: Theta lifts and local Maass forms

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In this paper, we construct Shintani lifts from integral weight weakly holomorphic modular forms to half-integral weight weakly holomorphic modular forms. Although defined by different methods, these coincide with the classical Shintani…

Number Theory · Mathematics 2014-05-20 Kathrin Bringmann , Pavel Guerzhoy , Ben Kane

We present completions of mock theta functions to harmonic weak Maass forms of weight $1/2$ and algebraic formulas for the coefficients of mock theta functions. We give several harmonic weak Maass forms of weight $1/2$ that have mock theta…

Number Theory · Mathematics 2020-10-23 David Klein , Jennifer Kupka

Mock modular forms, which give the theoretical framework for Ramanujan's enigmatic mock theta functions, play many roles in mathematics. We study their role in the context of modular parameterizations of elliptic curves $E/\mathbb{Q}$. We…

Number Theory · Mathematics 2015-09-10 Claudia Alfes , Michael Griffin , Ken Ono , Larry Rolen

We give a classification of the Harish-Chandra modules generated by the pullback to $\text{SL}_2(\mathbb R)$ of harmonic Maass forms for congruence subgroups of $\text{SL}_2(\mathbb Z)$ with exponential growth allowed at the cusps. We…

Number Theory · Mathematics 2016-09-23 Kathrin Bringmann , Stephen Kudla

We study the holomorphic projection of mixed mock modular forms involving sesquiharmonic Maass forms. As a special case, we numerically express the holomorphic projection of a function involving real quadratic class numbers multiplied by a…

Number Theory · Mathematics 2024-11-12 Michael Allen , Olivia Beckwith , Vaishavi Sharma

In the theory of harmonic Maass forms and mock modular forms, mock theta functions are distinguished examples which arose from $q$-hypergeometric examples of Ramanujan. Recently, there has been a body of work on higher depth mock modular…

Number Theory · Mathematics 2024-07-24 Joshua Males , Andreas Mono , Larry Rolen

We present some applications of the Kudla-Millson and the Millson theta lift. The two lifts map weakly holomorphic modular functions to vector valued harmonic Maass forms of weight $3/2$ and $1/2$, respectively. We give finite algebraic…

Number Theory · Mathematics 2020-06-19 Jan Hendrik Bruinier , Markus Schwagenscheidt

We define a regularized theta lift from SL_2 to orthogonal groups over totally real fields. It takes harmonic `Whittaker forms' to automorphic Green functions and weakly holomorphic Whittaker forms to meromorphic modular forms on orthogonal…

Number Theory · Mathematics 2011-02-21 Jan Hendrik Bruinier

We develop the theory of almost-holomorphic and quasimodular forms for orthogonal groups of a lattice of signature $(2,n)$ through orthogonal lowering and raising operators. The interactions with the regularized theta lift of Borcherds is a…

Algebraic Geometry · Mathematics 2025-05-15 Georg Oberdieck , Brandon Williams

Real-analytic Jacobi forms play key roles in different areas of mathematics and physics, but a satisfactory theory of such Jacobi forms has been lacking. In this paper, we fill this gap by introducing a space of harmonic Maass-Jacobi forms…

Number Theory · Mathematics 2014-03-25 Kathrin Bringmann , Martin Raum , Olav Richter

It is shown that each complex conjugate of a meromorphic modular form for $\mathrm{SL}_2(\mathbb{Z})$ of any complex weight $p$ occurs as the image of a harmonic modular form under the operator $2i y^p \, \partial_{\bar z}$. These harmonic…

Number Theory · Mathematics 2012-06-25 Roelof W. Bruggeman

We define a regularized Shintani theta lift which maps weight $2k+2$ ($k \in \Z, k \geq 0$) harmonic Maass forms for congruence subgroups to (sesqui-)harmonic Maass forms of weight $3/2+k$ for the Weil representation of an even lattice of…

Number Theory · Mathematics 2017-12-14 Claudia Alfes-Neumann , Markus Schwagenscheidt

By adapting the work of Kudla and Millson we obtain a lifting of cuspidal cohomology classes for the symmetric space associated to GO(V) for an indefinite rational quadratic space V of even dimension to holomorphic Siegel modular forms on…

Number Theory · Mathematics 2009-02-27 Tobias Berger

We give variants of lifting construction, which define new classes of modular forms on the Siegel upper half-space of complex dimension 3 with respect to the full paramodular groups (defining moduli of Abelian surfaces with arbitrary…

alg-geom · Mathematics 2016-08-30 Valeri A. Gritsenko , Viacheslav V. Nikulin

In the theory of integral weight harmonic Maass forms of manageable growth, two key differential operators, the Bol operator and the shadow operator, play a fundamental role. Harmonic Maass forms of manageable growth canonically split into…

Number Theory · Mathematics 2025-08-13 Kathrin Bringmann , Andreas Mono , Larry Rolen

We define a regularized lift from harmonic weak Maass forms of weight $2-N$ to differential forms of degree $N-1$ on the symmetric space $\SL_N(\R)/\SO(N)$, that are smooth outside of certain modular symbols. We show that this lift is…

Number Theory · Mathematics 2025-12-30 Romain Branchereau

In this paper we study restricted overpartitions and concave compositions. In several cases the resulting generating functions involve simultaneously modular forms, mock theta functions, mock Maass theta functions, and false theta…

Number Theory · Mathematics 2026-04-06 Koustav Banerjee , Kathrin Bringmann , Atul Dixit

Recall that a Maass wave form on the full modular group Gamma=PSL(2,Z) is a smooth gamma-invariant function u from the upper half-plane H = {x+iy | y>0} to C which is small as y \to \infty and satisfies Delta u = lambda u for some lambda…

Number Theory · Mathematics 2007-05-23 J. Lewis , D. Zagier

We construct some families of automorphic forms on Grassmannians which have singularities along smaller sub Grassmannians, using Harvey and Moore's extension of the Howe (or theta) correspondence to modular forms with poles at cusps. Some…

alg-geom · Mathematics 2015-06-24 Richard E. Borcherds

We introduce an L-series associated with harmonic Maass forms and prove their functional equations. We establish converse theorems for these L-series and, as an application, we formulate and prove a summation formula for the holomorphic…

Number Theory · Mathematics 2024-02-20 Nikolaos Diamantis , Min Lee , Wissam Raji , Larry Rolen