arXiv research

We prove the existence of manifolds with almost maximal volume entropy which are not hyperbolic.

The paper proves a quantitative rigidity result for spaces with specific curvature bounds.

The study shows almost maximal volume entropy rigidity for certain manifolds with integral Ricci curvature.

The paper proves rigidity results for Einstein manifolds with specific geometric constraints.

For $n$-dimensional Riemannian manifolds $M$ with Ricci curvature bounded below by $-(n-1)$, the volume entropy is bounded above by $n-1$. If $M$ is compact, it is known that the equality holds if and only if $M$ is hyperbolic. We extend this result to $\mathsf{RCD}^{\ast}(-(N-1),N)$ spaces. While the upper bound is st…

Quantitative rigidity theorem for Alexandrov spaces with curvature bounds.

Kahler manifolds with specific curvature properties are close to projective spaces.

Compactness theorem for manifolds with scalar curvature and entropy bounds.

We give several Bishop-Gromov relative volume comparisons with integral Ricci curvature which improve the results in \cite{PW1}. Using one of these volume comparisons, we derive an estimate for the volume entropy in terms of integral Ricci curvature which substantially improves an earlier estimate in \cite{Au2} and giv…

Let $M$ be a compact $n$-manifold of $\operatorname{Ric}_M\ge (n-1)H$ ($H$ is a constant). We are concerned with the following space form rigidity: $M$ is isometric to a space form of constant curvature $H$ under either of the following conditions: (i) There is $ρ>0$ such that for any $x\in M$, the open $ρ$-ball at $x^…

In this note we give a short proof to the rigidity of volume entropy. The result says that for a closed manifold with Ricci curvature bounded from below, if the universal cover has maximal volume entropy, then it is the space form. This theorem was first proved by F. Ledrappier and X. Wang in [1].

New volume comparison theorem for gradient Ricci almost solitons.

The paper proves finite topological type theorems for open manifolds with non-negative Ricci curvature and almost maximal local rewinding volume.

In this paper, we study the Ricci flat manifolds with maximal volume growth using Perelman's reduced volume of Ricci flow. We show that if $(M^n,g)$ is an noncompact complete Ricci flat manifold with maximal volume growth satisfying $|Rm|(x)\to 0$ as $d(x)=d_g(x,p)\to \infty$, then $M^n$ has the quadratic curvature dec…

Let $(M,g)$ be a compact manifold with Ricci curvature almost bounded from below and $π:\bar{M}\to M$ be a normal, Riemannian cover. We show that, for any nonnegative function $f$ on $M$, the means of $føπ$ on the geodesic balls of $\bar{M}$ are comparable to the mean of $f$ on $M$. Combined with logarithmic volume est…

We introduce the notion of a stationary random manifold and develop the basic entropy theory for it. Examples include manifolds admitting a compact quotient under isometries and generic leaves of a compact foliation. We prove that the entropy of an ergodic stationary random manifold is zero if and only if the manifold …

Almost-isometries are quasi-isometries with multiplicative constant one. Lifting a pair of metrics on a compact space gives quasi-isometric metrics on the universal cover. Under some additional hypotheses on the metrics, we show that there is no almost-isometry between the universal covers. We show that Riemannian mani…

The smallest $r$ so that a metric $r$-ball covers a metric space $M$ is called the radius of $M$. The volume of a metric $r$-ball in the space form of constant curvature $k$ is an upper bound for the volume of any Riemannian manifold with sectional curvature $\geq k$ and radius $\leq r$. We show that when such a manifo…

The paper studies minimal surface entropy on hyperbolic 3-manifolds and compares it to the hyperbolic case.

The main results of this paper consists of two parts. Firstly, we obtain an almost rigidity theorem which says that on a RCD(0, N) space, when a domain between two level sets of a distance function has almost maximal volume compared to that of a cylinder, then this portion is close to a cylinder as a metric space. Seco…

In \cite{LiWang2001complete1,LiWang2001complete2}, Li-Wang proved a splitting theorem for an n-dimensional Riemannian manifold with $Ric\geqslant -(n-1)$ and the bottom of spectrum $λ_0(M)=\frac{(n-1)^2}{4}$. For an n-dimensional compact manifold $M$ with $Ric\geqslant-(n-1)$ with the volume entropy $h(M)=n-1$, Ledrapp…

Defines a new geometric quantity for hyperbolic manifolds, showing it's well-defined and invariant.

Geodesics in curved spaces spread evenly over time.

Constructs ε-splitting maps for geodesic balls with non-negative Ricci curvature.

This paper optimizes trading strategies to minimize risk and maximize profit while accounting for market uncertainty.

We study simple root flows and Liouville currents for Hitchin representations. We show that the Liouville current is associated to the measure of maximal entropy for a simple root flow, derive a Liouville volume rigidity result, and construct a Liouville pressure metric on the Hitchin component.

LITE efficiently estimates Gaussian PoM with linear time and memory complexity.

Minimal volume entropy vanishes for mapping tori over 3-manifolds.

In this paper, we prove the concavity of the Shannon entropy power for the heat equation associated with the Laplacian or the Witten Laplacian on complete Riemannian manifolds with suitable curvature-dimension condition and on compact super Ricci flows. Under suitable curvature-dimension condition, we prove that the ri…

The Cayley hyperbolic space minimizes volume entropy among finite-volume metrics.

Motivated by Perelman's Pseudo Locality Theorem for the Ricci flow, we prove that if a Riemannian manifold has Ricci curvature bounded below in a metric ball which moreover has almost maximal volume, then in a smaller ball (in a quantified sense) it holds an almost-euclidean isoperimetric inequality. The result is actu…

Extended characterization of RAAGs with zero minimal volume entropy.

Entropy rigidity proven for 3D and higher convex projective manifolds.

Entropy derived from Colding's volume on Ricci-flat manifolds.

Minimal volume entropy vanishes or is positive under certain fiber growth conditions.

Study bounds self-shrinker entropy using Li-Yau volume and Colding-Minicozzi entropy.

Holomorphic automorphisms on hyperkähler manifolds with high entropy are Kummer examples.

Counterexamples found for volume entropy conjecture in hyperbolic 3-manifolds.

We introduce the volume entropy semi-norm in real homology and show that it satisfies functorial properties similar to the ones of the simplicial volume. Answering a question of M. Gromov, we prove that the volume entropy semi-norm is equivalent to the simplicial volume semi-norm in every dimension. We also establish a…

The study examines conditions for minimal volume entropy of simplicial complexes.

Improved bounds linking entropy and volume in hyperbolic 3-manifolds.

We extend the theory of Patterson-Sullivan measure to any regular covering of a compact manifold using the Busemann compactification and derive an integral formula for the volume entropy. As applications we prove some rigidity theorems for the volume entropy.

Study simplicial volume for fixed fundamental groups, finding gaps.

Study minimal volume entropy for free-by-cyclic groups and 2D right-angled Artin groups.

Characterizes metrics with finite total Q-curvature and introduces new volume entropy.

Paper compares two entropy concepts for finite presentation groups.

Perelman has discovered two integral quantities, the shrinker entropy $\cW$ and the (backward) reduced volume, that are monotone under the Ricci flow $\pa g_{ij}/\pa t=-2R_{ij}$ and constant on shrinking solitons. Tweaking some signs, we find similar formulae corresponding to the expanding case. The {\it expanding entr…

Proves uniqueness of measure of maximal entropy for geodesic flows on surfaces.