scholarly journals Meromorphic Modular Forms with Rational Cycle Integrals

2020 ◽  
Author(s):  
Steffen Löbrich ◽  
Markus Schwagenscheidt
Keyword(s):  
Modular Forms ◽  
Quadratic Forms ◽  
Positive Definite ◽  
Binary Quadratic Forms ◽  
Linear Combinations

Abstract We study rationality properties of geodesic cycle integrals of meromorphic modular forms associated to positive definite binary quadratic forms. In particular, we obtain finite rational formulas for the cycle integrals of suitable linear combinations of these meromorphic modular forms.

Computing coefficients of modular forms

2011 ◽  
Author(s):  
Bas Edixhoven
Keyword(s):  
Modular Form ◽  
Modular Forms ◽  
Quadratic Forms ◽  
Galois Representations ◽  
Theta Functions ◽  
Positive Definite ◽  
Hecke Operators ◽  
Linear Combinations ◽  
Tau Function ◽  
Arbitrary Weight

This chapter applies the main result on the computation of Galois representations attached to modular forms of level one to the computation of coefficients of modular forms. It treats the case of the discriminant modular form, that is, the computation of Ramanujan's tau-function at primes, and then deals with the more general case of forms of level one and arbitrary weight k, reformulated as the computation of Hecke operators Tⁿ as ℤ-linear combinations of the Tᵢ with i < k = 12. The chapter gives an application to theta functions of even, unimodular positive definite quadratic forms over ℤ.

On the region defined by | xy | ≤ 1, x2 + y2 ≤ t

1953 ◽  
Vol 49 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Kathleen Ollerenshaw
Keyword(s):  
Quadratic Forms ◽  
Positive Definite ◽  
Binary Quadratic Forms ◽  
Image Position

In this paper I find the critical lattices of the region Kt defined by the inequalities | xy | ≤ 1, x2 + y2 ≤ t (t > 0). I deduce in §9 the arithmetic minima of a pair of binary quadratic formswhere f1 is indefinite, f2 is positive definite, and f1, f2 are harmonically related, that is to sayand

On the number of representations of a positive integer as a sum of two binary quadratic forms

2014 ◽  
Vol 10 (06) ◽  
pp. 1395-1420 ◽  
Author(s):  
Şaban Alaca ◽  
Lerna Pehlivan ◽  
Kenneth S. Williams
Keyword(s):  
Positive Integer ◽  
Linear Combination ◽  
Quadratic Forms ◽  
Positive Definite ◽  
Definite Integral ◽  
Binary Quadratic Forms ◽  
Finite Linear Combination ◽  
Positive Integers ◽  
Finite Linear

Let ℕ denote the set of positive integers and ℤ the set of all integers. Let ℕ0 = ℕ ∪{0}. Let a1x2 + b1xy + c1y2 and a2z2 + b2zt + c2t2 be two positive-definite, integral, binary quadratic forms. The number of representations of n ∈ ℕ0 as a sum of these two binary quadratic forms is [Formula: see text] When (b1, b2) ≠ (0, 0) we prove under certain conditions on a1, b1, c1, a2, b2 and c2 that N(a1, b1, c1, a2, b2, c2; n) can be expressed as a finite linear combination of quantities of the type N(a, 0, b, c, 0, d; n) with a, b, c and d positive integers. Thus, when the quantities N(a, 0, b, c, 0, d; n) are known, we can determine N(a1, b1, c1, a2, b2, c2; n). This determination is carried out explicitly for a number of quaternary quadratic forms a1x2 + b1xy + c1y2 + a2z2 + b2zt + c2t2. For example, in Theorem 1.2 we show for n ∈ ℕ that [Formula: see text] where N is the largest odd integer dividing n and [Formula: see text]

ON A CORRESPONDENCE BETWEEN JACOBI CUSP FORMS AND ELLIPTIC CUSP FORMS

2013 ◽  
Vol 09 (04) ◽  
pp. 917-937 ◽  
Author(s):  
B. RAMAKRISHNAN ◽  
KARAM DEO SHANKHADHAR
Keyword(s):  
Modular Forms ◽  
Quadratic Forms ◽  
Cusp Forms ◽  
Jacobi Forms ◽  
Binary Quadratic Forms ◽  
Congruence Subgroups ◽  
Half Integral Weight ◽  
Integral Weight ◽  
Forms Of Higher Degree ◽  
Appl Math

In this paper, we prove a generalization of a correspondence between holomorphic Jacobi cusp forms of higher degree (matrix index) and elliptic cusp forms obtained by K. Bringmann [Lifting maps from a vector space of Jacobi cusp forms to a subspace of elliptic modular forms, Math. Z.253 (2006) 735–752], for forms of higher levels (for congruence subgroups). To achieve this, we make use of the method adopted by M. Manickam and the first author in Sec. 3 of [On Shimura, Shintani and Eichler–Zagier correspondences, Trans. Amer. Math. Soc.352 (2000) 2601–2617], who obtained similar correspondence in the degree one case. We also derive a similar correspondence in the case of skew-holomorphic Jacobi forms (matrix index and for congruence subgroups). Such results in the degree one case (for the full group) were obtained by N.-P. Skoruppa [Developments in the theory of Jacobi forms, in Automorphic Functions and Their Applications, Khabarovsk, 1988 (Acad. Sci. USSR, Inst. Appl. Math., Khabarovsk, 1990), pp. 168–185; Binary quadratic forms and the Fourier coefficients of elliptic and Jacobi modular forms, J. Reine Angew. Math.411 (1990) 66–95] and by M. Manickam [Newforms of half-integral weight and some problems on modular forms, Ph.D. thesis, University of Madras (1989)].

scholarly journals Modular forms of degree n and representation by quadratic forms

1979 ◽  
Vol 74 ◽  
pp. 95-122 ◽  
Author(s):  
Yoshiyuki Kitaoka
Keyword(s):  
Modular Forms ◽  
Quadratic Forms ◽  
Circle Method ◽  
Positive Definite ◽  
Siegel Modular Forms ◽  
Partial Result ◽  
Definite Integral ◽  
Integral Matrices

Let A(m), B(n) be positive definite integral matrices and suppose that B is represented by A over each p-adic integers ring Zp. Using the circle method or theory of modular forms in case of n = 1, B, if sufficiently large, is represented by A provided that m ≥ 5. The approach via the theory of modular forms has been extended by [7] to Siegel modular forms to obtain a partial result in the particular case when n = 2, m ≥ 7.

scholarly journals On Dirichlet series whose coefficients are class numbers of binary quadratic forms

1996 ◽  
Vol 142 ◽  
pp. 95-132 ◽  
Author(s):  
Boris A. Datskovsky
Keyword(s):  
Dirichlet Series ◽  
Quadratic Forms ◽  
Positive Definite ◽  
Equivalence Classes ◽  
Class Numbers ◽  
Definite Integral ◽  
Binary Quadratic Forms ◽  
Integral Solutions

For an integer d > 0 (resp. d < 0) let hd denote the number of Sl2(Z)-equivalence classes of primitive (resp. primitive positive-definite) integral binary quadratic forms of discriminant d. For where t and u are the smallest positive integral solutions of the equation t2 − du2 = 4 if d is a non-square and εd = 1 if d is a square.

scholarly journals Lower Bounds for the Principal Genus of Definite Binary Quadratic Forms

Integers ◽  
2010 ◽  
Vol 10 (2) ◽  
Author(s):  
Kimberly Hopkins ◽  
Jeffrey Stopple
Keyword(s):  
Lower Bounds ◽  
Quadratic Forms ◽  
Positive Definite ◽  
Binary Quadratic Forms

AbstractWe apply Tatuzawa's version of Siegel's theorem to derive two lower bounds on the size of the principal genus of positive definite binary quadratic forms.

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