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Related papers: Extremal K-contact metrics

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We show the contractibility of spaces of invariant Riemannian metrics of positive scalar curvature on compact connected manifolds of dimension at least two, with and without boundary and equipped with compact Lie group actions. On manifolds…

Differential Geometry · Mathematics 2025-06-23 Christian Baer , Bernhard Hanke

We calculate curvature tensors of metrics on the total spaces of holomorphic fibrations. Our main tool is a theory of Chern connections and curvature forms for possibly degenerate Hermitian forms on holomorphic vector bundles. We prove a…

Algebraic Geometry · Mathematics 2022-10-06 Gunnar Þór Magnússon

We use differential forms on loop spaces to prove that the fundamental group of certain geometric transformation groups is infinite. Examples include both finite and infinite dimensional Lie groups. The finite dimensional examples are the…

Differential Geometry · Mathematics 2025-10-03 Yoshiaki Maeda , Steven Rosenberg

We derive some integral inequalities for holomorphic maps between complex manifolds. As applications, some rigidity and degeneracy theorems for holomorphic maps without assuming any pointwise curvature signs for both the domain and target…

Differential Geometry · Mathematics 2020-12-07 Yashan Zhang

We extend the classical Donaldson-Fujiki interpretation of the scalar curvature as moment map in K\"ahler Geometry to the wider framework of locally conformally K\"ahler Geometry.

Differential Geometry · Mathematics 2023-06-30 Daniele Angella , Simone Calamai , Francesco Pediconi , Cristiano Spotti

We show the existence of a weak bi-invariant symmetric nondegenerate 2-form on the contact diffeomorphisms group $\mathcal{D}_\theta$ of a contact Riemannian manifold $(M,g,\theta)$ and study its properties. We describe the Euler's equation…

Differential Geometry · Mathematics 2014-08-29 N. K. Smolentsev

In this paper, we concern with the Sasaki analogue of Yau uniformization conjecture in a complete noncompact Sasakian manifold with nonnegative transverse bisectional curvature. As a consequence, we confirm that any $5$-dimensional complete…

Differential Geometry · Mathematics 2026-01-16 Shu-Cheng Chang , Yingbo Han , Chien Lin , Chin-Tung Wu

K-Theory for hermitian symmetric spaces of non-compact type, as developed recently by the authors, allows to put Cartan's classification into a homological perspective. We apply this method to the case of inductive limits of finite…

K-Theory and Homology · Mathematics 2016-09-23 Dennis Bohle , Wend Werner

We study a system of equations on a compact complex manifold, that couples the scalar curvature of a Kaehler metric with a spectral function of a first-order deformation of the complex structure. The system comes from an…

Differential Geometry · Mathematics 2022-07-08 Carlo Scarpa

Symplectic forms taming complex structures on compact manifolds are strictly related to Hermitian metrics having the fundamental form $\partial \bar \partial $-closed, i.e. to strong K\"ahler with torsion (${\rm SKT}$) metrics. It is still…

Differential Geometry · Mathematics 2012-06-11 Nicola Enrietti , Anna Fino , Luigi Vezzoni

We present a systematic and consistent construction of geometrothermodynamics by using Riemannian contact geometry for the phase manifold and harmonic maps for the equilibrium manifold. We present several metrics for the phase manifold that…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Hernando Quevedo , Alberto Sanchez , Safia Taj , Alejandro Vazquez

We give a survey of our recent work describing a method which combines the Sasaki join construction with the admissible K\"ahler construction of to obtain new extremal and new constant scalar curvature Sasaki metrics, including…

Differential Geometry · Mathematics 2015-06-04 Charles P. Boyer , Christina W. Tønnesen-Friedman

If a closed 3-manifold M supports a closed, nonsingular, irrational 1-form which linearly deforms into contact forms, then M supports a K-contact form. On the 3-torus, a closed nonsingular 1-form deforms linearly into contact forms if and…

Differential Geometry · Mathematics 2008-12-18 Hamidou Dathe , Philippe Rukimbira

We prove the existence of Sasakian metrics with positive Ricci curvature on certain highly connected odd dimensional manifolds. In particular, we show that manifolds homeomorphic to the 2k-fold connected sum of S^{2n-1} x S^{2n} admit…

Differential Geometry · Mathematics 2009-03-02 Charles P Boyer , Krzysztof Galicki

We define the operations of conformal change and elementary deformation in the setting of generalized complex geometry. Then we apply Swann's twist construction to generalized (almost) complex and Hermitian structures obtained by these…

Differential Geometry · Mathematics 2017-12-07 Vicente Cortés , Liana David

We study the geometry of almost contact pseudo-metric manifolds in terms of tensor fields $h:=\frac{1}{2}\pounds _\xi \varphi$ and $\ell := R(\cdot,\xi)\xi$, emphasizing analogies and differences with respect to the contact metric case.…

Differential Geometry · Mathematics 2018-06-01 Venkatesha , Devaraja Mallesha Naik , Mukut Mani Tripathi

For certain contact manifolds admitting a 1-periodic Reeb flow we construct a conjugation-invariant norm on the universal cover of the contactomorphism group. With respect to this norm the group admits a quasi-isometric monomorphism of the…

Symplectic Geometry · Mathematics 2016-10-28 Maia Fraser , Leonid Polterovich , Daniel Rosen

In this article we study almost contact manifolds admitting weakly Einstein metrics. We first prove that if a (2n+1)-dimensional Sasakian manifold admits a weakly Einstein metric then its scalar curvature $s$ satisfies $-6\leqslant s…

Differential Geometry · Mathematics 2019-09-04 Xiaomin Chen

In this paper we study sectional curvature of invariant hyper-Hermitian metrics on simply connected 4-dimensional real Lie groups admitting invariant hypercomplex structure. We give the Levi-Civita connections and explicit formulas for…

Differential Geometry · Mathematics 2016-12-30 H. R. Salimi Moghaddam

We are studying a relationship between isoparametric hypersurfaces in spheres with four distinct principal curvatures and the moment maps of certain Hamiltonian actions. In this paper, we consider the isoparametric hypersurfaces obtained…

Differential Geometry · Mathematics 2012-10-24 Shinobu Fujii , Hiroshi Tamaru