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Six-dimensional (2, 0) theory can be defined on a large class of six-manifolds endowed with some additional topological and geometric data (i.e. an orientation, a spin structure, a conformal structure, and an R-symmetry bundle with…

High Energy Physics - Theory · Physics 2015-05-20 Mans Henningson

We formalize the ``metric bundle'' viewpoint by defining, for any smooth $n$--manifold $M$, the open fiberwise cones $\mathcal{G}^{p,q}\subset S^2\Tstar M$ of nondegenerate symmetric bilinear forms with fixed signature $(p,q)$, and we…

Differential Geometry · Mathematics 2025-10-21 Shouvik Datta Choudhury

Let (M,g) be a 2-quasi-Einstein non-conformally flat semi-Riemannian manifold of dimension > 3. We prove that if its Riemann-Christoffel curvature tensor R is a linear combination of some Kulkarni-Nomizu tensors formed by the metric tensor…

Representing images and videos with Symmetric Positive Definite (SPD) matrices and considering the Riemannian geometry of the resulting space has proven beneficial for many recognition tasks. Unfortunately, computation on the Riemannian…

Computer Vision and Pattern Recognition · Computer Science 2014-11-18 Mehrtash T. Harandi , Mathieu Salzmann , Richard Hartley

Representing images and videos with Symmetric Positive Definite (SPD) matrices, and considering the Riemannian geometry of the resulting space, has been shown to yield high discriminative power in many visual recognition tasks.…

Computer Vision and Pattern Recognition · Computer Science 2016-05-23 Mehrtash Harandi , Mathieu Salzmann , Richard Hartley

Shifted partial derivative (SPD) methods are a central algebraic tool for circuit lower bounds, measuring the dimension of spaces of shifted derivatives of a polynomial. We develop the Shifted Partial Derivative Polynomial (SPDP) framework,…

Computational Complexity · Computer Science 2025-12-25 Darren J. Edwards

This article is an introductory work to a larger research project devoted to pure, applied and philosophical aspects of dimension theory. It concerns a novel approach toward an alternate dimension theory foundation: the point-dimension…

History and Philosophy of Physics · Physics 2022-06-14 Nadir Maaroufi , El Hassan Zerouali

In this paper, we study the quasi-Einstein and generalized quasi-Einstein warped products with a semi-symmetric non-metric connection. We give the expressions of the Ricci tensors and scalar curvatures for the bases and fibres. In some…

Differential Geometry · Mathematics 2015-05-14 Quan Qu

In this paper we take the perspective introduced by Case-Shu-Wei of studying warped product Einstein metrics through the equation for the Ricci curvature of the base space. They call this equation on the base the $m$-Quasi Einstein…

Differential Geometry · Mathematics 2011-01-25 Chenxu He , Peter Petersen , William Wylie

This rather technical paper presents some generalization of the results of recent publications \cite{Shirkov2010, DVPF2010, PFDV2010} where toy models of dimensional reduction of space-time were considered. Here we introduce and consider a…

Mathematical Physics · Physics 2010-12-17 Plamen Fiziev

We define the notion of an exceptional manifold to be a flat Riemannian manifold with boundary which supports a positive harmonic function satisfying simultaneously a zero Dirichlet condition and a constant (nonzero) Neumann condtion at the…

Mathematical Physics · Physics 2010-01-11 Frédéric Hélein , Laurent Hauswirth , Frank Pacard

A submanifold of a Riemannian manifold is called a parallel submanifold if its second fundamental form is parallel with respect to the van der Waerden-Bortolotti connection. From submanifold point of view, parallel submanifolds are the…

Differential Geometry · Mathematics 2019-10-22 Bang-Yen Chen

We define \textit{graded manifolds} as a version of supermanifolds endowed with an additional $\mathbb Z$-grading in the structure sheaf, called \textit{weight} (not linked with parity). Examples are ordinary supermanifolds, vector bundles…

Differential Geometry · Mathematics 2019-01-08 Theodore Voronov

A Riemannian manifold endowed with $k\ge2$ complementary pairwise orthogonal distributions is called a Riemannian almost $k$-product manifold. In the article, for the first time, we study the following problem: find a relationship between…

Differential Geometry · Mathematics 2023-02-15 Vladimir Rovenski , Pawel Walczak

We give necessary and sufficient conditions for warped product manifolds with 1-dimensional base, and in particular, for generalized Robertson-Walker spacetimes, to satisfy some generalized Einstein metric condition. We also construct…

Differential Geometry · Mathematics 2013-05-21 Kadri Arslan , Ryszard Deszcz , Ridvan Ezentas , Marian Hotloś , Cengizhan Murathan

We consider sphere bundles P and P' of totally null planes of maximal dimension and opposite self-duality over a 4-dimensional manifold equipped with a Weyl or Riemannian geometry. The fibre product PP' of P and P' is found to be…

dg-ga · Mathematics 2009-10-28 P. Nurowski

We extract a new class of paracontact paracomplex Riemannian manifolds arising from certain cone construction, call it para-Sasaki-like Riemannian manifold and give explicit examples. We define a hyperbolic extension of a paraholomorphic…

Differential Geometry · Mathematics 2021-05-21 Stefan Ivanov , Hristo Manev , Mancho Manev

We establish the necessary and sufficient conditions for constructing gradient Einstein-type warped metrics. One of these conditions leads us to a general Lichnerowicz equation with analytic and geometric coefficients for this class of…

Differential Geometry · Mathematics 2025-02-03 José Nazareno Vieira Gomes , Willian Isao Tokura

A minifold is a smooth projective $n$-dimensional variety such that its bounded derived category of coherent sheaves $\D^b(X)$ admits a semi-orthogonal decomposition into an exceptional collection of $n+1$ exceptional objects. In this paper…

Algebraic Geometry · Mathematics 2013-10-18 Sergey Galkin , Ludmil Katzarkov , Anton Mellit , Evgeny Shinder

It seems to be a common belief that the space in which we live is a space-time manifold of dimension at least four. In the present article we wish to draw attention to a slightly different possibility - a space-time pseudomanifold (or even…

General Relativity and Quantum Cosmology · Physics 2010-04-13 Amos Altshuler