Results 41 to 50 of about 28,809 (88)
Global and microlocal aspects of Dirac operators: Propagators and Hadamard states
Mathematische Nachrichten, Volume 298, Issue 9, Page 2942-2974, September 2025.Abstract We propose a geometric approach to construct the Cauchy evolution operator for the Lorentzian Dirac operator on Cauchy‐compact globally hyperbolic 4‐manifolds. We realize the Cauchy evolution operator as the sum of two invariantly defined oscillatory integrals—the positive and negative Dirac propagators—global in space and in time, with ...
Matteo Capoferri, Simone Murro
wiley +1 more source
Geometric Realization of the Segal--Sugawara Construction
, 2003 We apply the technique of localization for vertex algebras to the Segal-Sugawara construction of an ``internal'' action of the Virasoro algebra on affine Kac-Moody algebras.
Ben-Zvi, David, Frenkel, Edward
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About the density property in the space of continuous maps vanishing at infinity
, 2018 The conditions when C0(X)⊗Y is dense in C0(X ,Y ) in the compact-open topology on C0(X ,Y ) are given. This result is used for describing the properties of topological Segal algebras.
M. Abel
semanticscholar +1 more source
Stochastic integration with respect to cylindrical Lévy processes in Hilbert spaces
Journal of the London Mathematical Society, Volume 112, Issue 3, September 2025.Abstract In this work, we present a comprehensive theory of stochastic integration with respect to arbitrary cylindrical Lévy processes in Hilbert spaces. As cylindrical Lévy processes do not enjoy a semimartingale decomposition, our approach relies on an alternative approach to stochastic integration by decoupled tangent sequences.
Gergely Bodó, Markus Riedle
wiley +1 more source
, 2019 In this paper we initiate the study of enriched $\infty$-operads. We introduce several models for these objects, including enriched versions of Barwick's Segal operads and the dendroidal Segal spaces of Cisinski and Moerdijk, and show these are ...
Chu, Hongyi, Haugseng, Rune
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Traces on the uniform tracial completion of Z$\mathcal {Z}$‐stable C∗${\rm C}^*$‐algebras
Journal of the London Mathematical Society, Volume 111, Issue 6, June 2025.Abstract The uniform tracial completion of a C∗${\rm C}^*$‐algebra A$A$ with compact trace space T(A)≠∅$T(A) \ne \emptyset$ is obtained by completing the unit ball with respect to the uniform 2‐seminorm ∥a∥2,T(A)=supτ∈T(A)τ(a∗a)1/2$\Vert a\Vert _{2,T(A)}=\sup _{\tau \in T(A)} \tau (a^*a)^{1/2}$. The trace problem asks whether every trace on the uniform
Samuel Evington
wiley +1 more source
The Picard group in equivariant homotopy theory via stable module categories
Journal of Topology, Volume 18, Issue 2, June 2025.Abstract We develop a mechanism of “isotropy separation for compact objects” that explicitly describes an invertible G$G$‐spectrum through its collection of geometric fixed points and gluing data located in certain variants of the stable module category.
Achim Krause
wiley +1 more source
Semi-groups of operators and the Weierstrass theorem
, 1946 In this note we give a short proof of the generalization of M. H. Stone's representation of groups of unitary operators in Hubert space and show how it yields the theorem of Weierstrass on uniform approximation by polynomials.
N. Dunford, I. Segal
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Homological Lie brackets on moduli spaces and pushforward operations in twisted K‐theory
Journal of Topology, Volume 18, Issue 2, June 2025.Abstract We develop a general theory of pushforward operations for principal G$G$‐bundles equipped with a certain type of orientation. In the case G=BU(1)$G={B\mathrm{U}(1)}$ and orientations in twisted K‐theory, we construct two pushforward operations, the projective Euler operation, whose existence was conjectured by Joyce, and the projective rank ...
Markus Upmeier
wiley +1 more source
Approximate amenability of Schatten classes, Lipschitz algebras and second duals of Fourier algebras
, 2009 Amenability of any of the algebras described in the title is known to force them to be finite-dimensional. The analogous problems for \emph{approximate} amenability have been open for some years now.
Choi, Yemon, Ghahramani, Fereidoun
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