English
Related papers

Related papers: Boutet de Monvel's Calculus and Groupoids I

200 papers

We prove a number of results having to do with equipping type-I $\mathrm{C}^*$-algebras with compact quantum group structures, the two main ones being that such a compact quantum group is necessarily co-amenable, and that if the…

Operator Algebras · Mathematics 2020-08-11 Alexandru Chirvasitu , Jacek Krajczok , Piotr M. Sołtan

We give an algebraic/geometric characterization of the classical pseudodifferential operators on a smooth manifold in terms of the tangent groupoid and its natural $\mathbb{R}^\times_+$-action. Specifically, we show that a properly…

Differential Geometry · Mathematics 2017-07-28 Erik Van Erp , Robert Yuncken

It is a well-known result of Eymard that the Fourier-Stieltjes algebra of a locally compact group $G$ can be identified with the dual of the group $\cs$ $C^{*}(G)$. A corresponding result for a locally compact groupoid $G$ has been…

Operator Algebras · Mathematics 2011-02-03 Alan L. T. Paterson

If A is a C*-algebra, G a locally compact group, K{\subset}G a compact subgroup and {\alpha}:G{\to}Aut(A) a continuous homomorphism, let Ax_{{\alpha}}G denote the crossed product. In this paper we prove that Ax_{{\alpha}}G is nuclear…

Operator Algebras · Mathematics 2019-08-07 Raluca Dumitru , Costel Peligrad

We define the analytical and the topological indices for continuous families of operators in the C*-closure of the Boutet de Monvel algebra. Using techniques of C*-algebra K-theory and the Atiyah-Singer theorem for families of elliptic…

K-Theory and Homology · Mathematics 2015-07-16 Severino Melo , Elmar Schrohe , Thomas Schick

We prove that any countable discrete and torsion free subgroup of a general linear group over an arbitrary field or a similar subgroup of an almost connected Lie group satisfies the integral algebraic K-theoretic (split) Novikov conjecture…

K-Theory and Homology · Mathematics 2015-08-05 Snigdhayan Mahanta

We consider a finite-dimensional, locally finite CAT(0) cube complex X admitting a co-compact properly discontinuous countable group of automorphisms G. We construct a natural compact metric space B(X) on which G acts by homeomorphisms, the…

Geometric Topology · Mathematics 2011-05-10 Amos Nevo , Michah Sageev

Let $\mathcal C$ be category over a commutative ring $k$, its Hochschild-Mitchell homology and cohomology are denoted respectively $HH_*(\mathcal C)$ and $HH^*(\mathcal C).$ Let $G$ be a group acting on $\mathcal C$, and $\mathcal C[G]$ be…

K-Theory and Homology · Mathematics 2020-09-18 Claude Cibils , Eduardo N. Marcos

Given a connected semisimple Lie group $G$, Monod has recently proved that the measurable cohomology of the $G$-action $H^*_m(G \curvearrowright G/P)$ on the Furstenberg boundary $G/P$, where $P$ is a minimal parabolic subgroup, maps…

Group Theory · Mathematics 2025-04-15 Michelle Bucher , Alessio Savini

Given a unital $\boldsymbol{C}^{*}$-algebra $\mathcal{A}$, we prove the existence of the coproduct of two faithful operator $\mathcal{A}$-systems. We show that we can either consider it as a subsystem of an amalgamated free product of…

Operator Algebras · Mathematics 2025-04-25 Alexandros Chatzinikolaou

This paper introduces a canonical Polish groupoid associated to any separable unital C*-algebra, termed the unitary conjugation groupoid. It is defined as the semidirect product of the algebra's dual space by its unitary group, acting by…

Operator Algebras · Mathematics 2026-03-06 Shih-Yu Chang

Let $\mathcal K$ be a flag kernel on a homogeneous nilpotent Lie group $G$. We prove that operators $T$ of the form $T(f)= f*\mathcal K$ form an algebra under composition, and that such operators are bounded on $L^{p}(G)$ for $1<p<\infty$.

Functional Analysis · Mathematics 2011-08-02 Alexander Nagel , Fulvio Ricci , Elias M. Stein , Stephen Wainger

Given a manifold with corners $X$, we associates to it the corner structure simplicial complex $\Sigma_X$. Its reduced K-homology is isomorphic to the K-theory of the $C^*$-algebra $\mathcal{K}_b(X)$ of b-compact operators on $X$. Moreover,…

K-Theory and Homology · Mathematics 2022-10-06 Thomas Schick , Mario Velasquez

We show how to construct a graded locally compact Hausdorff \'etale groupoid from a C*-algebra carrying a coaction of a discrete group, together with a suitable abelian subalgebra. We call this groupoid the extended Weyl groupoid. When the…

Operator Algebras · Mathematics 2022-07-18 Toke Meier Carlsen , Efren Ruiz , Aidan Sims , Mark Tomforde

Given a separable unital C*algebra $C$, let $E_n$ denote the Hilbert module equal to the completion of the Schwartz space of rapidly decreasing smooth functions from $R^n$ to $C$ equipped with the $C$-valued inner product given by…

Operator Algebras · Mathematics 2007-05-23 Severino T. Melo , Marcela I. Merklen

The second author showed how Katsura's construction of the C*-algebra of a topological graph E may be twisted by a Hermitian line bundle L over the edge space E. The correspondence defining the algebra is obtained as the completion of the…

Operator Algebras · Mathematics 2017-01-25 Alex Kumjian , Hui Li

We consider a locally compact Hausdorff groupoid $G$, and twist by a more general locally compact Hausdorff abelian group $\Gamma$ rather than the complex unit circle $\mathbb{T}$. We investigate the construction of $C^*$-algebras in…

Operator Algebras · Mathematics 2025-11-14 Lisa Orloff Clark , Michael Ó Ceallaigh , Hung Pham

We show that the $p$-group complex of a finite group $G$ is homotopy equivalent to a wedge of spheres of dimension at most $n$ if $G$ contains a self-centralising normal subgroup $H$ which is isomorphic to a group of Lie type and Lie rank…

Group Theory · Mathematics 2026-02-25 Kevin Iván Piterman

The simplest case of a manifold with singularities is a manifold M with boundary, together with an identification of the boundary with a product M1 x P, where P is a fixed manifold. The associated singular space is obtained by collapsing P…

Differential Geometry · Mathematics 2011-03-10 Jonathan Rosenberg

In this manuscript we consider the extent to which an irreducible representation for a reductive Lie group can be realized as the sheaf cohomolgy of an equivariant holomorphic line bundle defined on an open invariant submanifold of a…

Representation Theory · Mathematics 2015-10-27 José Araujo , Tim Bratten
‹ Prev 1 4 5 6 7 8 10 Next ›