Results 71 to 80 of about 84,048 (226)

HYPERSURFACE EXCEPTIONAL SINGULARITIES [PDF]

open access: yesInternational Journal of Mathematics, 2001
This paper studies hypersurface exceptional singularities in [Formula: see text] defined by non-degenerate function. For each canonical hypersurface singularity, there exists a weighted homogeneous singularity such that the former is exceptional if and only if the latter is exceptional.
Shihoko Ishii, Yuri Prokhorov
openaire   +3 more sources

Singularities of spherical surface in R4

open access: yesOpen Mathematics
In this article, we mainly study the geometric properties of spherical surface of a curve on a hypersurface Σ\Sigma in four-dimensional Euclidean space.
Liu Haiming, Hua Yuefeng, Li Wanzhen
doaj   +1 more source

On a property of W4 -manifolds

open access: yesДифференциальная геометрия многообразий фигур, 2020
The properties of almost Hermitian manifolds belonging to the Gray — Hervella class W4 are considered. The almost Hermitian manifolds of this class were studied by such outstanding geometers like Alfred Gray, Izu Vaisman, and Vadim Feodorovich Kirichenko.
M.B. Banaru
doaj   +1 more source

Approximation of Dirac operators with δ${\delta }$‐shell potentials in the norm resolvent sense. I. Qualitative results

open access: yesMathematische Nachrichten, Volume 298, Issue 8, Page 2499-2546, August 2025.
Abstract In this paper, the approximation of Dirac operators with general δ$\delta$‐shell potentials supported on C2$C^2$‐curves in R2$\mathbb {R}^2$ or C2$C^2$‐surfaces in R3$\mathbb {R}^3$, which may be bounded or unbounded, is studied. It is shown under suitable conditions on the weight of the δ$\delta$‐interaction that a family of Dirac operators ...
Jussi Behrndt   +2 more
wiley   +1 more source

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

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  

Elucidating the Three‐Dimensional Structure of Piracetam through Rotational Spectroscopy

open access: yesChemistryOpen, Volume 14, Issue 8, August 2025.
Neutral molecules of the nootropic drug piracetam are generated by laser ablation and structurally characterized by microwave spectroscopy. Two conformers differing in the exo/endo configuration of the pyrrolidine ring are detected, with exo being the predominant form.
S. Mato   +4 more
wiley   +1 more source

On the equivalence of two curvature conditions for Lorentzian hypersurfaces

open access: yesArab Journal of Mathematical Sciences, 2017
Let n≥3. We show that semi-symmetry and Ricci-semisymmetry conditions are equivalent for any n-dimensional Lorentzian hypersurface in a Lorentzian space form with nonzero curvature.
Mohammed Guediri, Norah Alshehri
doaj   +1 more source

Maximum Mass Limit of Generalized MIT Compact Star: A Theoretical Study of Thin Shell Dynamics and Gravitational Lensing

open access: yesFortschritte der Physik, Volume 73, Issue 8, August 2025.
Abstract In this study, the properties, equilibrium, and stability of compact objects within the framework of teleparallel gravity with the generalized MIT bag model are investigated. By incorporating the modified field equations, the influence of the generalized bag constant on the structure and physical characteristics of quark stars and neutron ...
Sayantan Ghosh   +2 more
wiley   +1 more source

On symplectic hypersurfaces [PDF]

open access: yesAdvanced Studies in Pure Mathematics, 2018
A symplectic variety is a normal complex variety X with a holomorphic symplectic form ω on the regular part X reg and with rational Gorenstein sin-gularities. Affine symplectic varieties arise in many different ways such as closures of nilpotent orbits of a complex simple Lie algebra, as Slodowy slices to such nilpotent orbits or as symplectic ...
Lehn, Manfred   +3 more
openaire   +3 more sources

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