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Related papers: Non-Hilbertian tangents to Hilbertian spaces

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We investigate the homogeneity of topological subspaces of separable Hilbert space, akin to the spaces with all points rational or all points irrational, so-called Erd\H{o}s spaces. We provide a non-homogeneous example, that is based on one…

General Topology · Mathematics 2019-09-10 Klaas Pieter Hart , Jan van Mill

We give a classification of toric, Hermitian, Ricci flat, ALF Riemannian metrics in dimension 4, including metrics with conical singularities. The only smooth examples are on one hand the hyperKaehler ALF metrics, on the other hand, the…

Differential Geometry · Mathematics 2022-11-30 Olivier Biquard , Paul Gauduchon

An orbifold version of the Hitchin-Thorpe inequality is used to prove that certain weighted projective spaces do not admit orbifold Einstein metrics. Also, several estimates for the orbifold Yamabe invariants of weighted projective spaces…

Differential Geometry · Mathematics 2013-04-22 Jeff A. Viaclovsky

We give new inequalities for $A$-operator seminorm and $A$-numerical radius of semi-Hilbertian space operators and show that the inequalities obtained here generalize and improve on the existing ones. Considering a complex Hilbert space…

Functional Analysis · Mathematics 2024-08-14 Pintu Bhunia , Kallol Paul , Raj Kumar Nayak

In this paper we consider invariant Matsumoto metrics which are induced by invariant Riemannian metrics and invariant vector fields on homogeneous spaces then we give the flag curvature formula of them. Also we study the special cases of…

Differential Geometry · Mathematics 2015-07-09 H. R. Salimi Moghaddam

In this paper, we introduce the concept of an $m$-order $n$-dimensional generalized Hilbert tensor $\mathcal{H}_{n}=(\mathcal{H}_{i_{1}i_{2}\cdots i_{m}})$, $$ \mathcal{H}_{i_{1}i_{2}\cdots i_{m}}=\frac{1}{i_{1}+i_{2}+\cdots i_{m}-m+a},\…

Spectral Theory · Mathematics 2022-02-09 Wei Mei , Yisheng Song

Consider a Hilbert space obtained as the completion of the polynomials C[z} in m-variables for which the mnonomials are orthogonal. If the commuting weighted shifts defined by the coordinate functions are essentially normal, then the same…

Operator Algebras · Mathematics 2007-05-23 Ronald G. Douglas

We discuss the time evolution of physical finite dimensional systems which are modelled by non-hermitian Hamiltonians. We address both general non-hermitian Hamiltonians and pseudo-hermitian ones. We apply the theory of Krein Spaces to…

Mathematical Physics · Physics 2019-01-30 R. Ramirez , M. Reboiro

We review some regularity results for the Laplacian and $p$-Laplacian in metric measure spaces. The focus is mainly on interior H\"older, Lipschitz and second-regularity estimates and on spaces supporting a Poincar\'e inequality or having…

Analysis of PDEs · Mathematics 2025-02-04 Ivan Yuri Violo

We describe an example of an indefinite invariant Einstein metric on a solvmanifold which is not standard, and whose restriction on the nilradical is nondegenerate.

Differential Geometry · Mathematics 2025-05-20 Federico A. Rossi

We give a systematic study on the Hardy spaces of functions with values in the non-commutative $L^p$-spaces associated with a semifinite von Neumann algebra ${\cal}M.$ This is motivated by the works on matrix valued Harmonic Analysis…

Classical Analysis and ODEs · Mathematics 2007-06-13 Tao Mei

The support of wavelet transform associated with square integrable irreducible representation of a homogeneous space is shown to have infinite measure. Pointwise homogeneous approximation property for wavelet transform has been…

Representation Theory · Mathematics 2019-01-08 Jyoti Sharma , Ajay Kumar

Connections with (skew-symmetric) torsion on non-symmetric Riemannian manifold satisfying the Einstein metricity condition (NGT with torsion) are considered. It is shown that an almost Hermitian manifold is an NGT with torsion if and only…

Differential Geometry · Mathematics 2016-03-23 Stefan Ivanov , Milan Zlatanovic

Relative moduli spaces of periodic monopoles provide novel examples of Asymptotically Locally Flat hyperkahler manifolds. By considering the interactions between well-separated periodic monopoles, we infer the asymptotic behavior of their…

High Energy Physics - Theory · Physics 2009-11-07 Sergey A. Cherkis , Anton Kapustin

We classify non-reductive four-dimensional homogeneous conformally Einstein manifolds.

Differential Geometry · Mathematics 2017-03-27 E. Calviño-Louzao , E. García-Río , I. Gutiérrez-Rodríguez , R. Vázquez-Lorenzo

We study several homotopical and geometric properties of Maurer-Cartan spaces for L-infinity algebras which are not nilpotent, but only filtered in a suitable way. Such algebras play a key role especially in the deformation theory of…

Algebraic Topology · Mathematics 2015-04-08 Sinan Yalin

We show that Hermitian-Einstein metrics can be locally constructed by a map from (anti-)self-dual two-forms on Euclidean ${\mathbb R}^4$ to symmetric two-tensors introduced in "Gravitational instantons from gauge theory," H. S. Yang and M.…

High Energy Physics - Theory · Physics 2019-10-02 Kentaro Hara , Akifumi Sako , Hyun Seok Yang

This is an introduction to an algebraic construction of a gravity theory on noncommutative spaces which is based on a deformed algebra of (infinitesimal) diffeomorphisms. We start with some fundamental ideas and concepts of noncommutative…

High Energy Physics - Theory · Physics 2007-05-23 Frank Meyer

The Hamiltonians of $SU(2)$ and $SU(3)$ gauge theories in 3+1 dimensions can be expressed in terms of gauge invariant spatial geometric variables, i.e., metrics, connections and curvature tensors which are simple local functions of the…

High Energy Physics - Theory · Physics 2009-10-28 Daniel Z. Freedman

The differential calculus on `non-standard' $h$-Minkowski spaces is given. In particular it is shown that, for them, it is possible to introduce coordinates and derivatives which are simultaneously hermitian.

q-alg · Mathematics 2011-07-13 J. A. de Azcárraga , F. Rodenas