arXiv research

Proves existence and uniqueness of weighted metrics for smooth spaces.

Paper proves almost Schur Lemma on smooth metric measure spaces.

Researchers develop weighted GJMS operators for smooth metric measure spaces.

Study Ricci tensor on spaces with boundary, offering new curvature conditions.

Introduces Lie group actions in smoothing processes for currents and spaces with curvature.

Paper finds lower bounds for eigenvalues of Bi-drifted Laplacian on smooth metric measure spaces.

Heat kernels exist and are Hölder for rough metrics on smooth manifolds.

On a closed manifold of dimension greater than one, every smooth weak Riemannian metric on the space of smooth positive probability densities, that is invariant under the action of the diffeomorphism group, is a multiple of the Fisher--Rao metric.

We investigate a generalization of the so-called metric splitting of globally hyperbolic space-times to non-smooth Lorentzian manifolds and show the existence of this metric splitting for a class of wave-type space-times. Our approach is based on smooth approximations of non-smooth space-times by families (or sequences…

The paper proves gradient estimates for nonlinear parabolic equations on smooth metric measure spaces.

Generalizes Escobar-Riemann mapping problem for smooth metric measure spaces.

Gradient estimates for nonlinear parabolic equations on metric spaces.

A mass-type invariant for smooth metric measure spaces and its relation with the fractional Yamabe problem

We introduce and study the notion of the energy of a smooth metric measure space, which includes as special cases the Yamabe constant and Perelman's $ν$-entropy. We then investigate some properties the energy shares with these constants, in particular its relationship with the $κ$-noncollapsing property. Finally, we us…

For smooth metric measure spaces $(M, g, e^{-f} dvol)$ we prove a Liuoville-type theorem when the Bakry-Emery Ricci tensor is nonnegative. This generalizes a result of Yau, which is recovered in the case $f$ is constant. This result follows from a gradient estimate for f-harmonic functions on smooth metric measure spac…

Study on curved metrics on manifolds using smoothing theory.

Establishes smooth Ricci flows from convex surfaces in 3D space.

Proves existence of smooth metrics with specific curvature properties.

Locally homogeneous RCD spaces are shown to be smooth manifolds.

Gauduchon's theorem extended to singular spaces with smoothing.

We construct the moduli space of r-jets at a point of Riemannian metrics on a smooth manifold. The construction is closely related to the problem of classification of jet metrics via differential invariants. The moduli space is proved to be a differentiable space which admits a finite canonical stratification into smoo…

Smooth metric measure spaces have been studied from the two different perspectives of Bakry-Émery and Chang-Gursky-Yang, both of which are closely related to work of Perelman on the Ricci flow. These perspectives include a generalization of the Ricci curvature and the associated quasi-Einstein metrics, which include Ei…

We consider a geometric flow introduced by Gigli and Mantegazza which, in the case of smooth compact manifolds with smooth metrics, is tangen- tial to the Ricci flow almost-everywhere along geodesics. To study spaces with geometric singularities, we consider this flow in the context of smooth manifolds with rough metri…

We introduce the tractor formalism from conformal geometry to the study of smooth metric measure spaces. In particular, this gives rise to a correspondence between quasi-Einstein metrics and parallel sections of certain tractor bundles. We use this formulation to give a sharp upper bound on the dimension of the vector …

New Einstein RCD spaces found with cone singularities.

Study rough Riemannian metrics on manifolds, proving their connectedness and completeness.

In this paper we study fundamental properties of geodesic mappings with respect to the smoothness class of metrics. We show that geodesic mappings preserve the smoothness class of metrics. We study geodesic mappings of Einstein spaces.

The paper provides gradient estimates for nonlinear heat-type equations on smooth metric measure spaces.

Unified positive mass theorem and Dirac operator study on weighted manifolds.

It is known that on a closed manifold of dimension greater than one, every smooth weak Riemannian metric on the space of smooth positive densities that is invariant under the action of the diffeomorphism group, is of the form $G_μ(α,β)=C_1(μ(M)) \int_M \fracαμ\fracβμ\,μ+ C_2(μ(M)) \int_Mα\cdot \int_Mβ$ for some smoo…

We propose a definition of the weighted $σ_k$-curvature of a smooth metric measure space and justify it in two ways. First, we show that the weighted $σ_k$-curvature prescription problem is governed by a fully nonlinear second order elliptic PDE which is variational when $k=1,2$ or the smooth metric measure space is lo…

We determine the homeomorphism type of the space of smooth complete nonnegatively curved metrics on surfaces of positive Euler characteristic equipped with the topology of $C^γ$ uniform convergence on compact sets, when $γ$ is infinite or is not an integer. If $γ=\infty$, the space of metrics is homeomorphic to the sep…

Smooth Ricci flows from metric spaces can be extended to smooth solutions.

We first extend Cheeger-Colding Almost Splitting Theorem to smooth metric measure spaces. Arguments utilizing this extension of the Almost Splitting Theorem show that if a smooth metric measure space has almost nonnegative Bakry-Emery Ricci curvature and a lower bound on volume, then its fundamental group is almost abe…

Study isotropic solutions in smooth metric measure spaces with vacuum Einstein equations.

The paper provides new gradient estimates for solutions to a nonlinear elliptic equation on smooth metric measure spaces.

This is a survey on known results and open problems about Smooth and PL-Rigidity Problem for negatively curved locally symmetric spaces. We also review some developments about studying the basic topological properties of the space of negatively curved Riemannian metrics and the Teichmuller space of negatively curved me…

The study proves the stability of smooth embeddings of Riemannian metrics into Euclidean space.

We discuss the connection between the smooth and metric structure on quotient spaces, prove smoothness of isometries in special cases and discuss an application to a conjecture of Molino.

On a closed connected oriented manifold $M$ we study the space $\mathcal{M}_\|(M)$ of all Riemannian metrics which admit a non-zero parallel spinor on the universal covering. Such metrics are Ricci-flat, and all known Ricci-flat metrics are of this form. We show the following: The space $\mathcal{M}_\|(M)$ is a smooth …

Local smoothing of metrics with small curvature, removing Ricci curvature condition.

In this paper, we extend the Hamilton's gradient estimates \cite{har93} and a monotonicity formula of entropy \cite{ni04} for heat flows from smooth Riemannian manifolds to (non-smooth) metric measure spaces with appropriate Riemannian curvature-dimension condition.

Sharp ABP estimate on metric spaces via optimal transport.

Generalizes Aubin's result for Yamabe-type problem on smooth metric measure spaces.

Let $(M^{n+1},g,e^{-f}dμ)$ be a complete smooth metric measure space with $2\leq n\leq 6$ and Bakry-Émery Ricci curvature bounded below by a positive constant. We prove a smooth compactness theorem for the space of complete embedded $f$-minimal hypersurfaces in $M$ with uniform upper bounds on $f$-index and weighted vo…

Study classifies Einstein spaces and warped products in weighted geometry.

Defines mass for non-smooth hyperbolic spaces using a modified flow.

Study solves Yamabe problems on metric measure spaces with or without boundary.