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Let $X$ be the special fiber of a unitary Shimura variety of hyperspecial level at a prime $p$ inert in the totally real field $F$. Let $Y\to X$ be the associated flag space. For every $L$-dominant weight $\lambda$, let…

Number Theory · Mathematics 2026-05-05 Deding Yang

Higher order cohomology of arithmetic groups is expressed in terms of (g,K)-cohomology. Generalizing results of Borel, it is shown that the latter can be computed using functions of (uniform) moderate growth. A higher order versions of…

Number Theory · Mathematics 2008-05-16 Anton Deitmar

In this paper, we compute the homology group and cohomology algebra of various polyhedral product objects uniformly from the point of view of diagonal tensor product. As applications, we introduce the polyhedral product method into…

Algebraic Topology · Mathematics 2018-04-24 Qibing Zheng

We construct an Euler system associated to regular algebraic, essentially conjugate self-dual cuspidal automorphic representations of GL(3) over imaginary quadratic fields, using the cohomology of Shimura varieties for GU(2, 1).

Number Theory · Mathematics 2023-09-15 David Loeffler , Christopher Skinner , Sarah Livia Zerbes

We describe singular homology of a manifold $X$ via simplices $\sigma:\Delta_d\to X$ that satisfy Stokes' formula with respect to all differential forms. The notion is geared to the case of tame geometry (definable manifolds with respect to…

Number Theory · Mathematics 2023-10-17 Annette Huber

We present an unified construction for algebras and modules homologies and cohomologies, in the case of associative, commuttaive, Lie and Gerstenhaber algebras. We make a distinction between the linear part of the construction of algebras…

Quantum Algebra · Mathematics 2008-08-27 Ridha Chatbouri

Let X be a smooth projective curve over a field k of characteristic zero. The differential fundamental group of X is defined as the Tannakian dual to the category of vector bundles with (integrable) connections on X. This work investigates…

Algebraic Geometry · Mathematics 2025-03-26 Vo Quoc Bao , Phung Ho Hai , Dao Van Thinh

In the computation of the intersection cohomology of Shimura varieties, or of the $L^2$ cohomology of equal rank locally symmetric spaces, combinatorial identities involving averaged discrete series characters of real reductive groups play…

Combinatorics · Mathematics 2019-02-19 Richard Ehrenborg , Sophie Morel , Margaret Readdy

We study some automorphic cohomology classes of degree one on the Griffiths-Schmid varieties attached to some unitary groups in 3 variables. Using partial compactifications of those varieties, constructed by K. Kato and S. Usui, we define…

Number Theory · Mathematics 2007-05-23 Henri Carayol

We suggest a method of constructing special nonunitary representations of semisimple Lie groups using representations of Iwasawa subgroups. As a typical example, we study the group $U(2,2)$.

Representation Theory · Mathematics 2014-08-26 A. M. Vershik , M. I. Graev

It is known that the algebraic \deRham cohomology group $\hDR{i}(X_0/\Q)$ of a nonsingular variety $X_0/\Q$ has the same rank as the rational singular cohomology group $\h^i\sing(\Xh;\Q)$ of the complex manifold $\Xh$ associated to the base…

Algebraic Geometry · Mathematics 2007-05-23 Benjamin Friedrich

In this paper we construct various non-trivial and non-tautological cohomology classes on compactified and uncompactified strata of curves with a differential, by using the geometry of the boundary stratification of the moduli space of…

Algebraic Geometry · Mathematics 2026-02-27 Dawei Chen , Prabhat Devkota , Samuel Grushevsky , Martin Möller

In this informal expository note, we quickly introduce and survey compactifications of strata of holomorphic 1-forms on Riemann surfaces, i.e. spaces of translation surfaces. In the last decade, several of these have been constructed,…

Geometric Topology · Mathematics 2025-06-11 Benjamin Dozier

In this note we prove analogues of the main theorems of complex multiplication for abelian varieties for K3 surfaces. This is done by studying the field of definition of the period morphism for complex K3 surfaces. More precisely we relate…

Algebraic Geometry · Mathematics 2007-05-23 Jordan Rizov

We reproduce the quantum cohomology of toric varieties (and of some hypersurfaces in projective spaces) as the cohomology of certain vertex algebras with differential. The deformation technique allows us to compute the cohomology of the…

Algebraic Geometry · Mathematics 2007-05-23 F. Malikov , V. Schechtman

The principal aim of this paper is to construct torsion cohomology classes in the initial terms of a spectral sequence computing the cohomology of a Kottwitz-Harris-Taylor Shimura variety. Beside we produce some global congruences between…

Number Theory · Mathematics 2015-12-08 Pascal Boyer

The derivation algebras, automorphism groups and second cohomology groups of the generalized loop Schr\"{o}dinger-Virasoro algebras are completely determined in this paper.

Quantum Algebra · Mathematics 2015-09-08 Haibo Chen , Guangzhe Fan , Jianzhi Han , Yucai Su

In this short note, we prove a result about the non-generic part of the cohomology of certain compact unitary Shimura varieties for good $p$, partially extending a result of Boyer in the case of Harris--Taylor unitary Shimura varieties. Our…

Number Theory · Mathematics 2026-05-12 Kun Liu

For Shimura varieties of Hodge type, we show that there are natural isomorphisms between locally analytic complete cohomology groups and cohomology groups for flag varieties with coefficient which is given by their perfectoid covers. This…

Number Theory · Mathematics 2025-08-18 Kensuke Aoki

We consider special nonuntary represenation of the Iwasawa subgrouh with a nontrivial cohomology. For $p>2$ presunabley there are unitary representations with this property.

Representation Theory · Mathematics 2015-12-14 Anatoly Vershik , Mark Graev