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相关论文: Geometric Realizations of para-Hermitian curvature…

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We show that a Hermitian algebraic curvature model satisfies the Gray identity if and only if it is geometrically realizable by a Hermitian manifold. Furthermore, such a curvature model can in fact be realized by a Hermitian manifold of…

微分几何 · 数学 2008-12-16 M. Brozos-Vazquez , P. Gilkey , H. Kang , S. Nikcevic

We show any Riemannian curvature model can be geometrically realized by a manifold with constant scalar curvature. We also show that any pseudo-Hermitian curvature model, para-Hermitian curvature model, hyper-pseudo-Hermitian curvature…

微分几何 · 数学 2008-11-12 M. Brozos-Vazquez , P. Gilkey , H. Kang , S. Nikcevic , G. Weingart

We study geometric realization questions of curvature in the affine, Riemannian, almost Hermitian, almost para Hermitian, almost hyper Hermitian, almost hyper para Hermitian, Hermitian, and para Hermitian settings. We also express questions…

微分几何 · 数学 2009-04-08 M. Brozos-Vazquez , P. Gilkey , S. Nikcevic

We show that every Kaehler algebraic curvature tensor is geometrically realizable by a Kaehler manifold of constant scalar curvature. We also show that every para-Kaehler algebraic curvature tensor is geometrically realizable by a…

微分几何 · 数学 2015-05-14 M. Brozos-Vazquez , P. Gilkey , E. Merino

We determine the space of algebraic pseudo-Hermitian K\"ahler-Weyl curvature tensors and the space of para-Hermitian K\"ahler-Weyl curvature tensors in dimension 4 and show that every algebraic possibility is geometrically realizable. We…

微分几何 · 数学 2011-09-22 P. Gilkey , S. Nikcevic

The covariant derivative of the K\"ahler form of an almost pseudo-Hermitian or of an almost para-Hermitian manifold satisfies certain algebraic relations. We show, conversely, that any 3-tensor which satisfies these algebraic relations can…

微分几何 · 数学 2010-12-23 Miguel Brozos-Vázquez , Eduardo García-Río , Peter Gilkey , Luis Hervella

We show any Weyl curvature model can be geometrically realized by a Weyl manifold

微分几何 · 数学 2010-11-23 Peter Gilkey , Stana Nikcevic , Udo Simon

A cosmologically viable hypergeometric model in the modified gravity theory $f(R)$ is found from the need for asintoticity towards $\Lambda$CDM, the existence of an inflection point in the $f(R)$ curve, and the conditions of viability given…

广义相对论与量子宇宙学 · 物理学 2025-05-06 Roger Hurtado , Robel Arenas

We show that the Weyl structure of an almost-Hermitian Weyl manifold of dimension at least 6 is trivial if the associated curvature operator satisfies the Kaehler identity. Similarly if the curvature of an almost para-Hermitian Weyl…

微分几何 · 数学 2010-11-23 Peter Gilkey , Stana Nikcevic

We show that every Kaehler affine curvature model can be realized geometrically.

微分几何 · 数学 2010-07-16 M. Brozos-Vazquez , P. Gilkey , S. Nikcevic

The doubled target space of the fundamental closed string is identified with its phase space and described by an almost para-Hermitian geometry. We explore this setup in the context of group manifolds which admit a maximally isotropic…

高能物理 - 理论 · 物理学 2020-01-08 Falk Hassler , Dieter Lust , Felix J. Rudolph

Quasi-Hermitian quantum systems, including $\mathcal{PT}$-symmetric ones, can be mapped to equivalent Hermitian systems via a similarity transformation that redefines the inner product with a positive-definite metric operator. Although an…

量子物理 · 物理学 2026-05-12 Ming-Zhang Wang , Xu-Yang Hou , Hao Guo

In a previous paper, we have shown that the geometry of double field theory has a natural interpretation on flat para-K\"ahler manifolds. In this paper, we show that the same geometric constructions can be made on any para-Hermitian…

微分几何 · 数学 2015-06-11 Izu Vaisman

A local classification of the Hermitian manifolds with flat associated connection is given. Hermitian manifolds admitting locally a conformal metric with flat associated connection are characterized by a curvature identity. Locally…

微分几何 · 数学 2011-09-15 Georgi Ganchev , Ognian Kassabov

A general model for geometric structures on differentiable manifolds is obtained by deforming infinitesimal symmetries. Specifically, this model consists of a Lie algebroid, equipped with an affine connection compatible with the Lie…

微分几何 · 数学 2012-03-07 Anthony D. Blaom

Let (M,g,J) be a compact Hermitian manifold with a smooth boundary. Let $\Delta_p$ and $D_p$ be the realizations of the real and complex Laplacians on p forms with either Dirichlet or Neumann boundary conditions. We generalize previous…

微分几何 · 数学 2007-05-23 JeongHyeong Park

We prove the following results: An almost Hermitian manifold of indefinite metric is of pointwise constant holomorphic sectional curvature if the holomorphic sectional curvature is bounded from above and from below. If the antiholomorphic…

微分几何 · 数学 2010-08-12 Adrijan Borisov , Ognian Kassabov

A hermitian algebra is a unital associative ${\mathbb C}$-algebra endowed with an involution such that the spectra of self-adjoint elements are contained in ${\mathbb R}$. In the case of an algebra ${\mathcal A}$ endowed with a…

泛函分析 · 数学 2009-03-12 Daniel Beltita , Karl-Hermann Neeb

We work in both the complex and in the para-complex categories and examine (para)-K\"ahler Weyl structures in both the geometric and in the algebraic settings. The higher dimensional setting is quite restrictive. We show that any…

微分几何 · 数学 2012-04-04 P. Gilkey , S. Nikcevic

We give an elementary proof of the fact that any 4-dimensional para-Hermitian manifold admits a unique para-Kaehler--Weyl structure. We then use analytic continuation to pass from the para-complex to the complex setting and thereby show any…

微分几何 · 数学 2012-10-26 Peter Gilkey , Stana Nikcevic
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