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For $n\geq 25$, we construct a smooth metric $\tilde{g}$ on the standard $n$-dimensional sphere $\mathbb{S}^n$ such that there exists a sequence of smooth metrics $\{\tilde{g}_k\}_{k\in\mathbb{N}}$ conformal to $\tilde g$ where each $\tilde…

Analysis of PDEs · Mathematics 2025-06-30 Liuwei Gong , Yanyan Li

We use the cobordism category constructed in arXiv:1703.01047 to the study the homotopy type of the space of positive scalar curvature metrics on a spin manifold of dimension > 4. Our methods give an alternative proof and extension of a…

Algebraic Topology · Mathematics 2017-05-09 Nathan Perlmutter

Riemannian metrics of positive Ricci curvature were constructed on certain moment-angle manifolds.

Differential Geometry · Mathematics 2010-11-30 Ya. V. Bazaikin , I. V. Matvienko

Some curvature properties of Kahler manifolds of indefinite metrics are studied. Analogues of a Kulkarni's theorem are proved for such manifolds.

Differential Geometry · Mathematics 2010-08-12 Ognian Kassabov , Adrijan Borisov

We obtain two types of results on positive scalar curvature metrics for compact spin manifolds that are even dimensional. The first type of result are obstructions to the existence of positive scalar curvature metrics on such manifolds,…

Differential Geometry · Mathematics 2020-07-30 Michael Hallam , Varghese Mathai

We show that there are infinitely many pairwise nonhomothetic, complete, periodic metrics with constant scalar curvature that are conformal to the round metric on $S^n\setminus S^k$, where $k < \frac{n-2}{2}$. These metrics are obtained by…

Differential Geometry · Mathematics 2025-10-07 João H. Andrade , Jeffrey S. Case , Paolo Piccione , Juncheng Wei

We initiate the study of an analogue of the Yamabe problem for complex manifolds. More precisely, fixed a conformal Hermitian structure on a compact complex manifold, we are concerned in the existence of metrics with constant Chern scalar…

Differential Geometry · Mathematics 2017-09-05 Daniele Angella , Simone Calamai , Cristiano Spotti

We prove that any complete non-compact K\"ahler surface with positive sectional curvature is biholomorphic to $\mathbb{C}^2$, establishing the two dimensional case of the weaker form of Yau's uniformisation conjecture. In contrast to all…

Differential Geometry · Mathematics 2026-04-14 Ved Datar , Vamsi Pritham Pingali , Harish Seshadri

Physical reasons suggested in \cite{Ha-Ha} for the \emph{Quantum Gravity Problem} lead us to study \emph{type-changing metrics} on a manifold. The most interesting cases are \emph{Transverse Riemann-Lorentz Manifolds}. Here we study the…

Differential Geometry · Mathematics 2015-06-26 E. Aguirre , V. Fernández , J. Lafuente

Some examples of three-dimensional metrics of constant curvature defined by solutions of nonlinear integrable differential equations and their generalizations are constructed. The properties of Riemann extensions of the metrics of constant…

Differential Geometry · Mathematics 2009-11-11 V. Dryuma

We show that in every dimension $n \geq 8$, there exists a smooth closed manifold $M^n$ which does not admit a smooth positive scalar curvature ("psc") metric, but $M$ admits an $\mathrm{L}^\infty$-metric which is smooth and has psc outside…

Differential Geometry · Mathematics 2025-11-06 Simone Cecchini , Georg Frenck , Rudolf Zeidler

There has been a lot of interests in Positive Mass Theorems for singular metrics on smooth manifolds. We prove a positive mass theorem for asymptotically flat (AF) spin manifolds with isolated conical singularities or more generally horn…

Differential Geometry · Mathematics 2023-11-01 Xianzhe Dai , Yukai Sun , Changliang Wang

We show that if $(M,\omega)$ is any compact K\"ahler manifold, then the blowup of $M$ at any point furnishes a K\"ahler metric with scalar curvature globally and arbitrarily $C^0$-close to the scalar curvature of $\omega$. It follows that…

Differential Geometry · Mathematics 2026-01-28 Garrett M. Brown

We provide a general B\"ochner type formula which enables us to prove some rigidity results for $V$-static spaces. In particular, we show that an $n$-dimensional positive static triple with connected boundary and positive scalar curvature…

Differential Geometry · Mathematics 2018-10-17 H. Baltazar , E. Ribeiro

We introduce Riemannian metrics of positive scalar curvature on manifolds with Baas-Sullivan singularities, prove a corresponding homology invariance principle and discuss admissible products. Using this theory we construct positive scalar…

Differential Geometry · Mathematics 2021-04-07 Bernhard Hanke

Any compact manifold with positive scalar curvature has an associated asymptotically flat metric constructed using the Green's function of the conformal Laplacian, and the mass of this metric is an important geometric invariant. An explicit…

Differential Geometry · Mathematics 2015-06-18 Jeff A. Viaclovsky

We prove a canonical variation-type result for submersion metrics with positive intermediate Ricci curvatures. This can then be used in conjunction with surgery techniques to establish the existence of metrics with positive intermediate…

Differential Geometry · Mathematics 2025-01-24 Philipp Reiser , David J. Wraith

For the real, continuous, isotropic and positive definite kernels on a product of spheres, one may consider not only its usual strict positive definiteness but also strict positive definiteness restrict to the points of the product that…

Classical Analysis and ODEs · Mathematics 2015-05-15 Jean C. Guella , Valdir A. Menegatto

Following P. M. H. Wilson's paper on sectional curvatures of Kahler moduli, we consider a natural Riemannian metric on a hypersurface f=1 in a real vector space, defined using the Hessian of a homogeneous polynomial f. We give examples to…

Differential Geometry · Mathematics 2007-05-23 Burt Totaro

In this paper, we prove that, a compact complex manifold $X$ admits a smooth Hermitian metric with positive (resp. negative) scalar curvature if and only if $K_X$ (resp. $K_X^{-1}$) is not pseudo-effective. On the contrary, we also show…

Differential Geometry · Mathematics 2017-10-12 Xiaokui Yang