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Related papers: Generalized Unitaries and the Picard Group

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We present a short and elegant proof of the complete theory of strict representations of the algebra B^a(E) of all adjointable operators on a Hilbert B-module E by operators on a Hilbert C-module F. Aanalogue for W*-modules and normal…

Operator Algebras · Mathematics 2007-05-23 P. S. Muhly , M. Skeide , B. Solel

Traditionally, homotopy groups in $G$-equivariant stable homotopy theory have been graded over $\text{RO}(G)$, the real representation ring of $G$. It is arguably more natural to grade homotopical structures over the Picard group of the…

Algebraic Topology · Mathematics 2025-12-19 Jesse Keyes , Jordan Sawdy

We study the invariant algebraic D-modules on an affine variety under the action of an algebraic group.For linear algebraic groups with the multiplication action by themselves, such D-modules correspond to representations of their Lie…

Representation Theory · Mathematics 2025-05-20 Yunsong Wei

We study closedness of the range, adjointability and generalized invertibility of modular operators between Hilbert modules over locally C*-algebras of coefficients. Our investigations and the recent results of M. Frank [Characterizing…

Operator Algebras · Mathematics 2011-08-31 Kamran Sharifi

We introduce the Picard group of corings. We extend the well-known exact sequence from algebras and coalgebras over fields to corings. We extend the Aut-Pic property to corings and we give some new examples of corings having this property.…

Rings and Algebras · Mathematics 2007-05-23 Mohssin Zarouali-Darkaoui

We consider positive semidefinite kernels valued in the $*$-algebra of adjointable operators on a VE-space (Vector Euclidean space) and that are invariant under actions of $*$-semigroups. A rather general dilation theorem is stated and…

Functional Analysis · Mathematics 2017-02-06 Serdar Ay , Aurelian Gheondea

Algebra and representation theory in modular tensor categories can be combined with tools from topological field theory to obtain a deeper understanding of rational conformal field theories in two dimensions: It allows us to establish the…

Category Theory · Mathematics 2008-11-26 Jürg Fröhlich , Jürgen Fuchs , Ingo Runkel , Christoph Schweigert

Let $G$ be a finite group and $k$ a field of prime characteristic $p$. We give a complete classification of endotrivial complexes, i.e. determine the Picard group $\mathcal{E}_k(G)$ of the tensor-triangulated category…

Group Theory · Mathematics 2025-11-11 Sam K. Miller

We obtain a set of generalized eigenvectors that provides a generalized spectral decomposition for a given unitary representation of a commutative, locally compact topological group. These generalized eigenvectors are functionals belonging…

Mathematical Physics · Physics 2007-05-23 M. Gadella , F. Gomez , S. Wickramasekara

In this paper we consider shift operators, self-adjoint, unitary and normal operators on the standard module over a unital C*-algebra A. We define various generalized spectra in A of these operators, give description of such spectra of…

Operator Algebras · Mathematics 2020-07-13 Stefan Ivkovic

We consider representations of rational Cherednik algebras which are particular ideals in the ring of polynomials. We investigate convergence of the integrals which express the Gaussian inner product on these representations. We derive that…

Representation Theory · Mathematics 2012-01-31 Misha Feigin , Constantin Shramov

We determine explicitly the Picard groups of the universal Jacobian stack and of its compactification over the stack of stable curves. Along the way, we prove some results concerning the gerbe structure of the universal Jacobian stack over…

Algebraic Geometry · Mathematics 2014-05-05 Margarida Melo , Filippo Viviani

We investigate the normal subgroups of the groups of invertibles and unitaries in the connected component of the identity. By relating normal subgroups to closed two-sided ideals we obtain a "sandwich condition" describing all the closed…

Operator Algebras · Mathematics 2016-03-08 Leonel Robert

We study the Picard groups of moduli spaces in positive characteristics and we give a "$p$-adic" proof that the Picard group of moduli of vector bundles of fixed determinant is isomorphic to the group of integers. Along the way we prove…

Algebraic Geometry · Mathematics 2010-05-18 Kirti Joshi , V. B. Mehta

Bergman has given the following abstract characterisation of the inner automorphisms of a group $G$: they are exactly those automorphisms of $G$ which can be extended functorially along any homomorphism $G \rightarrow H$ to an automorphism…

Category Theory · Mathematics 2019-07-25 Richard Garner

Let $G$ be a discrete countable group, and let $\Gamma$ be an almost normal subgroup. In this paper we investigate the classification of (projective) unitary representations $\pi$ of $G$ into the unitary group of the Hilbert space…

Operator Algebras · Mathematics 2014-12-25 Florin Radulescu

Consider a smooth connected algebraic group $G$ acting on a normal projective variety $X$ with an open dense orbit. We show that Aut($X$) is a linear algebraic group if so is $G$; for an arbitrary $G$, the group of components of Aut($X$) is…

Algebraic Geometry · Mathematics 2019-11-21 Michel Brion

We introduce a class of quantum integrable systems generalizing the Gaudin model. The corresponding algebras of quantum Hamiltonians are obtained as quotients of the center of the enveloping algebra of an affine Kac-Moody algebra at the…

Quantum Algebra · Mathematics 2011-04-07 B. Feigin , E. Frenkel , V. Toledano-Laredo

For $4 \nmid L$ and $g$ large, we calculate the integral Picard groups of the moduli spaces of curves and principally polarized abelian varieties with level $L$ structures. In particular, we determine the divisibility properties of the…

Algebraic Geometry · Mathematics 2019-12-19 Andrew Putman

Admissible vectors for unitary representations of locally compact groups are the basis for group-frame and covariant coherent state expansions. Main tools in the study of admissible vectors have been Plancherel and central integral…

Functional Analysis · Mathematics 2019-11-12 F. Gómez-Cubillo , S. Wickramasekara