Results 41 to 50 of about 41,546 (140)
On the embeddability of real hypersurfaces into hyperquadrics [PDF]
Advances in Mathematics, 2018 In this paper, we provide {\em effective} results on the non-embeddability of real-analytic hypersurfaces into a hyperquadric. We show that, for any $N >n \geq 1$, the defining functions $φ(z,\bar z,u)$ of all real-analytic hypersurfaces $M=\{v=φ(z,\bar z,u)\}\subset\mathbb C^{n+1}$ containing Levi-nondegenerate points and locally transversally ...
Kossovskiy, Ilya, Xiao, Ming
openaire +2 more sources
In–out propagator in de Sitter space from general boundary quantum field theory
Physics Letters B, 2015 The general boundary formulation of quantum theory is applied to quantize a real massive scalar field in de Sitter space. The space–time region where the dynamics of the field takes place is bounded by one spacelike hypersurface of constant conformal de ...
Daniele Colosi
doaj +1 more source
Transversal Jacobi Operators in Almost Contact Manifolds
Mathematics, 2020 Along a transversal geodesic γ whose tangent belongs to the contact distribution D, we define the transversal Jacobi operator Rγ=R(·,γ˙)γ˙ on an almost contact Riemannian manifold M.
Jong Taek Cho, Makoto Kimura
doaj +1 more source
Analytic regularity of CR maps into spheres
, 2003 Let $M$ be a connected real-analytic hypersurface in $\C^N$ and $\S$ the unit real sphere in $\C^{N'}$, $N'> N\geq 2$. Assume that $M$ does not contain any complex-analytic hypersurface of $\C^N$ and that there exists at least one strongly pseudoconvex ...
Mir, Nordine
core +4 more sources
Geodesics on Calabi-Yau manifolds and winding states in nonlinear sigma models
Frontiers in Physics, 2013 We conjecture that a non-flat D-real-dimensional compact Calabi-Yau manifold, such as a quintic hypersurface with D=6, or a K3 manifold with D=4, has locally length minimizing closed geodesics, and that the number of these with length less than L grows ...
Peng eGao, Michael R. Douglas
doaj +1 more source
Algebraicity of Global Real Analytic Hypersurfaces
Geometriae Dedicata, 2006 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Kurdyka, Krzysztof, Kucharz, Wojciech
openaire +3 more sources
Diffeomorphism Invariant Integrable Field Theories and Hypersurface Motions in Riemannian Manifolds
, 1995 We discuss hypersurface motions in Riemannian manifolds whose normal velocity is a function of the induced hypersurface volume element and derive a second order partial differential equation for the corresponding time function $\tau(x)$ at which the ...
Chen Y. G. +4 more
core +1 more source
Optimal Gain Selection for the Arbitrary‐Order Homogeneous Differentiator
International Journal of Robust and Nonlinear Control, EarlyView.ABSTRACT Differentiation of noisy signals is a relevant and challenging task. Widespread approaches are the linear high‐gain observer acting as a differentiator and Levant's robust exact differentiator with a discontinuous right‐hand side. We consider the family of arbitrary‐order homogeneous differentiators, which includes these special cases.
Benjamin Calmbach +2 more
wiley +1 more source
Calibrated entanglement entropy
Journal of High Energy Physics, 2017 The Ryu-Takayanagi prescription reduces the problem of calculating entanglement entropy in CFTs to the determination of minimal surfaces in a dual anti-de Sitter geometry.
I. Bakhmatov +4 more
doaj +1 more source
Parametrization of local CR automorphisms by finite jets and applications
, 2006 For any real-analytic hypersurface M in complex euclidean space of dimension >= 2 which does not contain any complex-analytic subvariety of positive dimension, we show that for every point p in M the local real-analytic CR automorphisms of M fixing p can
Lamel, Bernhard, Mir, Nordine
core +3 more sources