Homological methods in certain Picard group computations
نویسندگان
چکیده
Let G be a connected complex semisimple Lie group, Γ cocompact, irreducible and torsionless lattice in K maximal compact subgroup of G. Assume acts by left multiplication right on MΓ=Γ﹨G, X=G/K XΓ=Γ﹨X. In this article we prove that for any n≥0, the composition Hn(XΓ,C)→Hn(MΓ,C)→Hn(MΓ,OMΓ) is an isomorphism. As application when simply connected, compute Picard group MΓ cases rank(G) =1,2. More precisely show if =1, Pic(MΓ)=(Cr/Zr)⊕A =2, then Pic(MΓ)≅A via first Chern class map, where A torsion H2(MΓ,Z) r rank Γ/[Γ,Γ].
منابع مشابه
Homological Computations in PBW Modules
In this paper the Poincaré–Birkhoff–Witt (PBW) rings are characterized. Gröbner bases techniques are also developed for these rings. An explicit presentation of Exti (M,N) is provided when N is a centralizing bimodule. Mathematics Subject Classifications (2000): 16Z05, 16E30.
متن کاملHomological Computations for Term Rewriting Systems
An important problem in universal algebra consists in finding presentations of algebraic theories by generators and relations, which are as small as possible. Exhibiting lower bounds on the number of those generators and relations for a given theory is a difficult task because it a priori requires considering all possible sets of generators for a theory and no general method exists. In this art...
متن کاملThe Picard group
Why should a number theorist be interested in algebraic geometry? In this course we hope to demonstrate one very good reason, by showing essentially geometric reasons why certain Diophantine equations fail to have solutions. But we will begin by placing the study of Diophantine equations into the context of algebraic geometry, to see how techniques from many different realms of mathematics can ...
متن کاملIntegral Cohomology of Certain Picard Modular Surfaces
Let Γ̄ be the Picard modular group of an imaginary quadratic number field k and let D be the associated symmetric space. Let Γ ⊂ Γ̄ be a congruence subgroup. We describe a method to compute the integral cohomology of the locally symmetric space Γ\D. The method is implemented for the cases k = Q(i) and k = Q( √ −3), and the cohomology is computed for various Γ.
متن کاملOn the Homological Dimension of Certain Ideals
1. Introduction. We present two closely related results connecting homological dimension theory and the ideal theory of noetherian rings. The first, Proposition 4.1, asserts that the only ideals of finite homological dimension in a local ring whose associated prime ideals all have grade one are of the form aR:bR. The second, Proposition 4.3, asserts that if R is a noetherian integral domain, th...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Bulletin Des Sciences Mathematiques
سال: 2022
ISSN: ['0007-4497', '1952-4773']
DOI: https://doi.org/10.1016/j.bulsci.2022.103178