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Related papers: Composition and $L^2$-boundedness of flag kernels

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We introduce completely bounded kernels taking values in L(A,B) where A and B are C*-algebras. We show that if B is injective such kernels have a Kolmogorov decomposition precisely when they can be scaled to be completely contractive, and…

Operator Algebras · Mathematics 2012-12-17 Tirthankar Bhattacharyya , Michael A. Dritschel , Christopher S. Todd

In this paper, we take advantage of a reinterpretation of differential modules admitting a flag structure as a special class of perturbations of complexes. We are thus able to leverage the machinery of homological perturbation theory to…

Commutative Algebra · Mathematics 2024-08-07 Keller VandeBogert

We find upper and lower bounds of the multiplicities of irreducible admissible representations $\pi$ of a semisimple Lie group $G$ occurring in the induced representations $Ind_H^G\tau$ from irreducible representations $\tau$ of a closed…

Representation Theory · Mathematics 2013-10-09 Toshiyuki Kobayashi , Toshio Oshima

New identities and congruences involving the ranks and cranks of partitions are proved. The proof depends on a new partial differential equation connecting their generating functions.

Number Theory · Mathematics 2007-05-23 A. O. L. Atkin , F. G. Garvan

We prove pointwise and $L^p$ gradient estimates for the heat kernel on the bounded and unbounded Vicsek set and applications to Sobolev inequalities are given. We also define a Hodge semigroup in that setting and prove estimates for its…

Analysis of PDEs · Mathematics 2024-09-25 Fabrice Baudoin , Li Chen

We show that there is a ${SL_n}$-stable closed subset of an affine Schubert variety in the infinite dimensional Flag variety (associated to the Kac-Moody group ${\widehat{SL_n}}$) which is a natural compactification of the cotangent bundle…

Algebraic Geometry · Mathematics 2022-03-29 V. Lakshmibai , C. S. Seshadri , R. Singh

We study heat kernel rigidity for the Lie group $\operatorname{SU}\left( 2 \right)$ kernel equipped with a sub-Riemannian structure. We prove that a metric measure space equipped with a heat kernel of a special form is bundle-isometric to…

Analysis of PDEs · Mathematics 2025-01-13 Maria Gordina , Jing Wang

To numerically approximate Borel probability measures by finite atomic measures, we study the spectral decomposition of discrepancy kernels when restricted to compact subsets of $\mathbb{R}^d$. For restrictions to the Euclidean ball in odd…

Numerical Analysis · Mathematics 2019-09-30 Josef Dick , Martin Ehler , Manuel Gräf , Christian Krattenthaler

We consider rational projective homogeneous varieties over an algebraically closed field of positive characteristic, namely quotients of a semi-simple group by a possibly non-reduced parabolic subgroup. We determine the group scheme…

Algebraic Geometry · Mathematics 2025-07-08 Matilde Maccan

We use group homology to define invariants in algebraic K-theory and in an analogue of the Bloch group for Q-rank one lattices and for some other geometric structures. We also show that the Bloch invariants of CR structures and of flag…

Geometric Topology · Mathematics 2012-10-29 Inkang Kim , Sungwoon Kim , Thilo Kuessner

We provide pointwise upper bounds for the transition kernels of semigroups associated with a class of systems of nondegenerate elliptic partial differential equations with unbounded coefficients with possibly unbounded diffusion…

Analysis of PDEs · Mathematics 2024-12-23 Davide Addona , Luca Lorenzi , Marianna Porfido

Let k be a global field and let k_v be the completion of k with respect to v, a non-archimedean place of k. Let \mathbf{G} be a connected, simply-connected algebraic group over k, which is absolutely almost simple of k_v-rank 1. Let…

Group Theory · Mathematics 2007-10-23 A. W. Mason , A. Premet , B. Sury , P. A. Zalesskii

In this paper, we prove that every homogeneous Landsberg surface has isotropic flag curvature. Using this special form of the flag curvature, we prove a rigidity result on homogeneous Landsberg surface. Indeed, we prove that every…

Differential Geometry · Mathematics 2021-07-14 Akbar Tayebi , Behzad Najafi

We establish a finiteness property of the quantum K-ring of the complete flag manifold.

Algebraic Geometry · Mathematics 2017-11-23 David Anderson , Linda Chen , Hsian-Hua Tseng

We prove Behrend's conjecture on the rationality of the canonical reduction of principal bundles and reductive group schemes for classical groups and give new bounds for the conjecture for exceptional groups. However we find a…

Algebraic Geometry · Mathematics 2008-11-03 Jochen Heinloth

The symmetries described by Pin groups are the result of combining a finite number of discrete reflections in (hyper)planes. The current work shows how an analysis using geometric algebra provides a picture complementary to that of the…

Mathematical Physics · Physics 2025-10-16 Martin Roelfs , Steven De Keninck

The Hecke algebras and quantum group of affine type A admit geometric realizations in terms of complete flags and partial flags over a local field, respectively. Subsequently, it is demonstrated that the quantum group associated to partial…

Representation Theory · Mathematics 2024-03-08 Quanyong Chen , Zhaobing Fan , Qi Wang

We prove that for a simply laced group, the closure of the Borel conjugacy class of any nilpotent element of height $2$ in its conjugacy class is normal and admits a rational resolution. We extend this, using Frobenius splitting techniques,…

Algebraic Geometry · Mathematics 2016-04-11 Martin Bender , Nicolas Perrin

In the spirit of an earlier result of M\"uller on the Heisenberg group we prove a restriction theorem on a certain class of two step nilpotent Lie groups. Our result extends that of M\"uller also in the framework of the Heisenberg group.

Functional Analysis · Mathematics 2023-02-14 Valentina Casarino , Paolo Ciatti

In this paper we propose two guiding principles that suggest a number of conjectures (some now proved) about various forms of rigidity for moduli spaces arising in algebraic geometry. Such conjectures have group-theoretic, topological and…

Algebraic Geometry · Mathematics 2023-02-14 Benson Farb