arXiv research

4-manifolds with non-hyperbolic geometry are ordered.

Study finite group actions on manifolds with non-zero degree maps to nilmanifolds.

First the title could be also understood as ``3-manifolds related by non-zero degree maps" or "Degrees of maps between 3-manifolds" for some aspects in this survey talk. The topology of surfaces was completely understood at the end of 19th century, but maps between surfaces kept to be an active topic in the 20th centur…

We define a new class of irreducible groups, called groups not infinite-index presentable by products or not IIPP. We prove that certain aspherical manifolds with fundamental groups not IIPP do not admit maps of non-zero degree from direct products. This extends previous results of Kotschick and Loeh, providing new cla…

We address a conjecture that $π_1$-surjective maps between closed aspherical 3-manifolds having the same rank on $π_1$ must be of non-zero degree. The conjecture is proved for Seifert manifolds, which is used in constructing the first known example of minimum Haken manifold. Another motivation is to study epimorphisms …

We show any set of degrees can be realized by manifolds.

In this paper we use character variety methods to study homomorphisms between the fundamental groups of 3-manifolds, in particular those induced by non-zero degree maps. A {\it knot manifold} is a compact, connected, irreducible, orientable 3-manifold whose boundary is an incompressible torus. A {\it virtual epimorphis…

We prove that rationally essential manifolds with suitably large fundamental groups do not admit any maps of non-zero degree from products of closed manifolds of positive dimension. Particular examples include all manifolds of non-positive sectional curvature of rank one and all irreducible locally symmetric spaces of …

Proves rigidity for maps between manifolds using degree theory and current developments.

Odd-dimensional manifolds have contact maps of non-zero degree.

Paper proves non-vanishing of index map for low-degree cohomology classes.

We study the map degrees between quasitoric 4-manifolds. Our results rely on Theorems proved by Duan and Wang. We determine the set D (M, N) of all possible map degrees from M to N when M and N are certain quasitoric 4-manifolds. The obtained sets of integers are interesting, e. g. those representable as the sum of two…

We estimate the linear isoperimetric constants of an n-dimensional ellipse. Using these estimates and a technique of Gromov, we estimate the Hopf and linking invariants of Lipschitz maps from ellipses to round spheres. Using these estimates, we give a lower bound for the k-dilation of degree non-zero maps between ellip…

Thom-Pontrjagin constructions are used to give a computable necessary and sufficient condition when a homomorphism $φ: H^n(L;Z)\to H^n(M;Z)$ can be realized by a map $f:M\to L$ of degree $k$ for closed $(n-1)$-connected $2n$-manifolds $M$ and $L$, $n>1$. A corollary is that each $(n-1)$-connected $2n$-manifold admits s…

Abstract: Study continuous maps between Kähler manifolds, proving a gap theorem.

We give a simple procedure to estimate the smallest Lipshitz constant of a degree 1 map from a Riemannian 2-sphere to the unit 2-sphere, up to a factor of 10. Using this procedure, we are able to prove several inequalities involving this Lipshitz constant. For instance, if the smallest Lipshitz constant is at least 1, …

A natural problem in the theory of 3-manifolds is the question of whether two 3-manifolds are homeomorphic or not. The aim of this paper is to study this problem for the class of closed Haken manifolds using degree one maps. To this purpose we introduce an invariant $τ(N)=({\rm Vol}(N),\|N\|)$ where $\|N\|$ denotes th…

Let M be a closed 3-manifold which can be triangulated with N simplices. We prove that any map from M to a genus 2 surface has Hopf invariant at most C^N. Let X be a closed oriented hyperbolic 3-manifold with injectivity radius less than epsilon at one point. If there is a degree non-zero map from M to X, then we prove…

Study geometric manifolds in arbitrary dimensions, focusing on maps and diffeomorphisms.

Maps between circle bundles are studied, proving fiber-preserving and finiteness results for mapping degrees.

Proves strong version of Hopf problem for hyperbolic circle bundles.

No regular algebraic hypersurfaces with non-zero constant mean curvature in Euclidean spaces are found.

Study proves rigidity of harmonic maps from 2-torus to complex projective space.

A map between manifolds is an isometry if it's Lipschitz and scalar curvature bounded.

In this paper we study some fourth order elliptic equation involving the critical Sobolev exponent, related to the prescription of a fourth order conformal invariant on the standard sphere. We use a topological method to prove the existence of at least a solution when the function to be prescribed is close to a constan…

In this paper, we study the behavior of the maximal homological degree of the non-zero Khovanov homology groups under twisting.

Maps are shown to be Riemannian products with Ricci-flat fibers.

We establish three rank inequalities for the reduced flavor of Heegaard Floer homology of Seifert fibered integral homology spheres. Combining these inequalities with the known classifications of non-zero degree maps between Seifert fibered spaces, we prove that a map f from Y' to Y between Seifert homology spheres yie…

We define the Kodaira dimension for $3$-dimensional manifolds through Thurston's eight geometries, along with a classification in terms of this Kodaira dimension. We show this is compatible with other existing Kodaira dimensions and the partial order defined by non-zero degree maps. For higher dimensions, we explore th…

No algebraic 3rd degree hypersurfaces in Euclidean spaces have constant mean curvature.

Study shows non-abelian free groups' 4th cohomology is non-zero.

Method sanitizes IFM in CNN layers to control privacy loss.

Proves rigidity of maps between manifolds with scalar curvature constraints.

Constructs chiral rational homology spheres with hyperbolic groups.

The four-dimensional sphere is uniquely rigid in terms of scalar curvature.

In this paper we state and prove a higher index theorem for an odd-dimensional connected spin riemannian manifold $(M,g)$ which is partitioned by an oriented closed hypersurface $N$. This index theorem generalizes a theorem due to N. Higson and J. Roe in the context of Hilbert modules. Then we apply this theorem to pro…

Uniform proof of $π_1$-injectivity for certain maps in low dimensions.

We prove a finiteness result for the $\partial$-patterned guts decomposition of all 3-manifolds obtained by splitting a given orientable, irreducible and $\partial$-irreducible 3-manifold along a closed incompressible surface. Then using the Thurston norm, we deduce that the JSJ-pieces of all 3-manifolds dominated by a…

This paper adresses the following problem: Given a closed orientable three-manifold M, are there at most finitely many closed orientable three-manifolds 1-dominated by M? We solve this question for the class of closed orientable graph manifolds. More presisely the main result of this paper asserts that any closed orien…

The energy function associated to harmonic maps between surfaces is convex at critical points.

Maps on foliated manifolds decrease area and scalar curvature is negative.

The paper explores graphons of line graphs from sparse finite graphs.

New bounded cohomology classes found for exact forms on curved manifolds.

Defines and classifies Thurston geometries and connects simplicial volume to Kodaira dimension.

Develops degree theory for orbifolds, a generalization of differential topology.

Study on harmonic maps between cones, linking degrees to graph Laplacian eigenvalues.

We examine the local super trace asymptotics for the de Rham complex defined by an arbitrary super connection on the exterior algebra. We show, in contrast to the situation in which the connection in question is the Levi-Civita connection, that these invariants are generically non-zero in positive degree and that the c…

For harmonic maps of degree 2, a similar quantitative stability estimate does not hold uniformly.