Results 31 to 40 of about 21,501 (172)
Para-Kähler-Einstein 4-manifolds and non-integrable twistor distributions
Geometriae Dedicata, 2022 We study the local geometry of 4-manifolds equipped with a para-Kähler-Einstein (pKE) metric, a special type of split-signature pseudo-Riemannian metric, and their associated twistor distribution, a rank 2 distribution on the 5-dimensional total space of
G. Bor, Omid Makhmali, P. Nurowski
semanticscholar +1 more source
On the K‐stability of blow‐ups of projective bundles
Journal of the London Mathematical Society, Volume 113, Issue 5, May 2026.Abstract We investigate the K‐stability of certain blow‐ups of P1$\mathbb {P}^1$‐bundles over a Fano variety V$V$, where the P1$\mathbb {P}^1$‐bundle is the projective compactification of a line bundle L$L$ proportional to −KV$-K_V$ and the center of the blow‐up is the image along a positive section of a divisor B$B$ also proportional to L$L$. When V$V$
Daniel Mallory
wiley +1 more source
Fortschritte der Physik, Volume 74, Issue 4, April 2026.Abstract String theory has strong implications for cosmology, implying the absence of a cosmological constant, ruling out single‐field slow‐roll inflation, and that black holes decay. The origins of these statements are elucidated within the string‐theoretical swampland programme.
Kay Lehnert
wiley +1 more source
Hyperkähler and quaternionic Kähler geometry
, 1990 A quaternion-Hermitian manifold, of dimension at least 12, with closed fundamental 4-form is shown to be quaternionic Kähler. A similar result is proved for 8-manifolds.
Swann, Andrew F.
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Continuity Equation of Transverse Kähler Metrics on Sasakian Manifolds
MathematicsWe introduce the continuity equation of transverse Kähler metrics on Sasakian manifolds and establish its interval of maximal existence. When the first basic Chern class is null (resp. negative), we prove that the solution of the (resp.
Yushuang Fan, Tao Zheng
doaj +1 more source
A Miyaoka–Yau inequality for hyperplane arrangements in CPn$\mathbb {CP}^n$
Journal of the London Mathematical Society, Volume 113, Issue 4, April 2026.Abstract Let H$\mathcal {H}$ be a hyperplane arrangement in CPn$\mathbb {CP}^n$. We define a quadratic form Q$Q$ on RH$\mathbb {R}^{\mathcal {H}}$ that is entirely determined by the intersection poset of H$\mathcal {H}$. Using the Bogomolov–Gieseker inequality for parabolic bundles, we show that if a∈RH$\mathbf {a}\in \mathbb {R}^{\mathcal {H}}$ is ...
Martin de Borbon, Dmitri Panov
wiley +1 more source
Quasi-Kahler Chern-flat manifolds and complex 2-step nilpotent Lie algebras [PDF]
, 2012 The study of quasi-Kaehler Chern-flat almost Hermitian manifolds is strictly related to the study of anti-bi-invariant almost complex Lie algebras.
Lauret, J. +2 more
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The cosymplectic Chern–Hamilton conjecture
Journal of the London Mathematical Society, Volume 113, Issue 2, February 2026.Abstract In this paper, we study the Chern–Hamilton energy functional on compact cosymplectic manifolds, fully classifying in dimension 3 those manifolds admitting a critical compatible metric for this functional. This is the case if and only if either the manifold is co‐Kähler or if it is a mapping torus of the 2‐torus by a hyperbolic toral ...
Søren Dyhr +3 more
wiley +1 more source
Quaternion Kähler flat manifolds [PDF]
, 2001 We give a general method to construct hyperkähler and quaternion Kähler flat manifolds with holonomy Z2k.
Miatello, Roberto J. +5 more
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Novel Theorems on Spacetime Admitting Pseudo‐W2 Curvature Tensor
Journal of Mathematics, Volume 2026, Issue 1, 2026.This paper investigates spacetime manifolds admitting a pseudo‐W2 curvature tensor. We show that a pseudo‐W2 flat spacetime is an Einstein manifold and therefore has constant curvature. Moreover, when the manifold satisfies the Einstein field equations (EFE), with a cosmological constant, the associated energy–momentum tensor is covariantly constant ...
B. B. Chaturvedi +3 more
wiley +1 more source