Results 71 to 80 of about 73,367 (201)

Gradient Ricci Solitons on Spacelike Hypersurfaces of Lorentzian Manifolds Admitting a Closed Conformal Timelike Vector Field

open access: yesMathematics
In this article, we investigate Ricci solitons occurring on spacelike hypersurfaces of Einstein Lorentzian manifolds. We give the necessary and sufficient conditions for a spacelike hypersurface of a Lorentzian manifold, equipped with a closed conformal ...
Norah Alshehri, Mohammed Guediri
doaj   +1 more source

Quantum fields and entanglement on a curved lightfront

open access: yesPhysics Letters B, 2015
We consider field quantization on an arbitrary null hypersurface in curved spacetime. We discuss the de Sitter horizon as the simplest example, relating the horizon quantization to the standard Fock space in the cosmological patch.
Illan Halpern, Yasha Neiman
doaj   +1 more source

A geometric flow on null hypersurfaces of Lorentzian manifolds

open access: yesTopological Algebra and its Applications, 2022
We introduce a geometric flow on a screen integrable null hypersurface in terms of its local second fundamental form. We use it to give an alternative proof to the vorticity free Raychaudhuri’s equation for null hypersurface, as well as establishing ...
Massamba Fortuné, Ssekajja Samuel
doaj   +1 more source

Stochastic Dynamics From Maximum Entropy in Action Space

open access: yesFortschritte der Physik, Volume 74, Issue 5, May 2026.
ABSTRACT We develop an information‐theoretic formulation of stochastic dynamics in which the fundamental stochastic variable is the total action connecting spacetime points, rather than individual paths. By maximizing Shannon entropy over a joint distribution of actions and endpoints, subject to normalization and a constraint on the mean action, we ...
Fabricio Souza Luiz   +3 more
wiley   +1 more source

Surface and form in contemporary architecture / Paviršius ir forma šiuolaikinėje architektūroje

open access: yesMokslas: Lietuvos Ateitis, 2012
Architectural form in contemporary architecture gains more and more independence and visual difference from the tectonic structure of the building. Many researchers of contemporary architecture separate a building’s “skin” from its carcass.
Algimantas M. Mačiulis
doaj   +1 more source

On the Construction of Multivariate Drought Indices: Theoretical Foundations and Practical Implications

open access: yesWater Resources Research, Volume 62, Issue 5, May 2026.
Abstract Drought indices represent essential tools for monitoring and evaluating drought conditions and evolution. Univariate indices employ the Probability Integral Transform to map data onto the standard Gaussian domain. Extending such a Gaussian normalization procedure to multivariate settings requires the usage of the Kendall distribution function ...
Carlo De Michele   +3 more
wiley   +1 more source

Construction of the field of Norden — Timofeev planes of hypersurfacese quipped with distributions

open access: yesДифференциальная геометрия многообразий фигур, 2018
In the projective space the research of a hypersurface with three stron­gest mutual subbundles continues. The field of the invariant Norden — Ti­mofeev planes is constructed that is internally attached to the hypersurface.
N. Eliseeva
doaj  

Curvatures of hypersurfaces

open access: yesLietuvos Matematikos Rinkinys, 2010
In this article we generalize some classical formulas for curvatures of hypersurfaces in the n-dimensional Euclidean space using the homogeneous formulas.
Kazimieras Navickis
doaj   +1 more source

Convergent normal form for real hypersurfaces at generic Levi degeneracy [PDF]

open access: yes, 2014
We construct a complete convergent normal form for a real hypersurface in $\CC{N},\,N\geq 2$ at generic Levi degeneracy. This seems to be the first convergent normal form for a Levi-degenerate hypersurface.
Kossovskiy, Ilya, Zaitsev, Dmitri
core  

The universal family of punctured Riemann surfaces is Stein

open access: yesBulletin of the London Mathematical Society, Volume 58, Issue 5, May 2026.
Abstract We show that the universal Teichmüller family V(g,n)$V(g,n)$ of compact Riemann surfaces of genus g⩾0$g\geqslant 0$ with n>0$n>0$ punctures is a Stein manifold. We describe its basic function‐theoretic properties and pose some challenging questions. We show, in particular, that the space of fibrewise algebraic functions on the universal family
Franc Forstnerič
wiley   +1 more source

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