arXiv research

Study of psc metrics via block diffeomorphisms and cubical sets.

Models for self-equivalences and diffeomorphisms of manifolds.

The paper studies pseudo-isotopies of spherical 3-manifolds and computes ranks of certain groups.

In this paper we prove a stability theorem for block diffeomorphisms of 2d-dimensional manifolds that are connected sums of S^d x S^d. Combining this with a recent theorem of S. Galatius and O. Randal-Williams and Morlet's lemma of disjunction, we determine the homology of the classifying space of their diffeomorphism …

Tautological classes, or generalised Miller-Morita-Mumford classes, are basic characteristic classes of smooth fibre bundles, and have recently been used to describe the rational cohomology of classifying spaces of diffeomorphism groups for several types of manifolds. We show that rationally tautological classes depend…

Let $G$ be a connected Lie group and $Γ\subset G$ a lattice. Connection curves of the homogeneous space $M=G/Γ$ are the orbits of one parameter subgroups of $G$. To $block$ a pair of points $m_1,m_2 \in M$ is to find a finite set $B \subset M\setminus \{m_1, m_2 \}$ such that every connecting curve joining $m_1$ and $m…

Let $φ: M\to M$ be a diffeomorphism of a $C^\infty$ compact connected manifold, and $X$ its mapping torus. There is a natural fibration $p:X\to S^1$, denote by $ξ\in H^1(X, \mathbb{Z})$ the corresponding cohomology class. Let $λ\in \mathbb{Z}^*$. Consider the endomorphism $φ_k^*$ induced by $φ$ in the cohomology of $M$…

Round handles are affiliated with smooth 4-manifolds in two major ways: 5-dimensional round handles appear extensively as the building blocks in cobordisms between 4-manifolds, whereas 4-dimensional round handles are the building blocks of broken Lefschetz fibrations on them. The purpose of this article is to shed more…

The signed volume function for polyhedra can be generalized to a mean volume function for volume elements by averaging over the triangulations of the underlying polyhedron. If we consider these up to translation and scaling, the resulting quotient space is diffeomorphic to a sphere. The mean volume function restricted …

The study determines fiber homotopy trivial bundles and their impact on curvature.

Smooth manifolds have equivalent diffeomorphism groups if and only if they are diffeomorphic.

Constructs entropy-minimizing pseudo-Anosov diffeomorphisms on K3 surfaces.

This paper presents a novel Block Iterative Bayesian Algorithm (Block-IBA) for reconstructing block-sparse signals with unknown block structures. Unlike the existing algorithms for block sparse signal recovery which assume the cluster structure of the nonzero elements of the unknown signal to be independent and identic…

This letter presents a novel Block Bayesian Hypothesis Testing Algorithm (Block-BHTA) for reconstructing block sparse signals with unknown block structures. The Block-BHTA comprises the detection and recovery of the supports, and the estimation of the amplitudes of the block sparse signal. The support detection and rec…

Proposes a Nested Block Model to unify various network block models.

We examine the recovery of block sparse signals and extend the framework in two important directions; one by exploiting signals' intra-block correlation and the other by generalizing signals' block structure. We propose two families of algorithms based on the framework of block sparse Bayesian learning (BSBL). One fami…

The study proves diffeomorphisms can be localized to simpler submanifolds.

Paper derives explicit expression of Alekseev-Meinrenken diffeomorphism.

According to Pixton, there are Morse-Smale diffeomorphisms of the 3-sphere which have no energy function, that is a Lyapunov function whose critical points are all periodic points of the diffeomorphism. We introduce the concept of quasi-energy function for a Morse-Smale diffeomorphism as a Lyapunov function with the le…

We determine the Riemannian manifolds for which the group of exact volume preserving diffeomorphisms is a totally geodesic subgroup of the group of volume preserving diffeomorphisms, considering right invariant $L^2$-metrics. The same is done for the subgroup of Hamiltonian diffeomorphisms as a subgroup of the group of…

Generalizes $π_2$-diffeomorphism finiteness to non-zero first homotopy groups.

Study on group cocycles for volume-preserving diffeomorphisms.

We theoretically investigate the convergence rate and support consistency (i.e., correctly identifying the subset of non-zero coefficients in the large sample limit) of multiple kernel learning (MKL). We focus on MKL with block-l1 regularization (inducing sparse kernel combination), block-l2 regularization (inducing un…

Book introduces Hofer's metric on symplectic diffeomorphisms.

Study local diffeomorphisms of conformal circles in pseudo-Riemannian manifolds.

Survey on foliations and diffeomorphism groups.

The paper shows Thurston geometries don't support Anosov diffeomorphisms.

New exotic 4D spaces found using knot slicing techniques.

The paper explores the transitivity of orbifold diffeomorphisms.

The paper proves $n$-transitivity for equivariant diffeomorphisms of manifolds.

New 4-manifolds with exotic diffeomorphisms found.

Study exotic Dehn twists in 4-manifolds, producing first known exotic diffeomorphisms.

New Lie groups found for Poisson diffeomorphisms.

SympFormer accelerates attention blocks using inertial dynamics on density spaces.

In [2], the first author constructed the first known examples of exotic minimal symplectic $\CP#5\CPb$ and minimal symplectic 4-manifold that is homeomorphic but not diffeomorphic to $3\CP#7\CPb$. The construction in [2] uses Y. Matsumoto's genus two Lefschetz fibrations on $M = \mathbb{T}^{2}\times \mathbb{S}^{2} #4\C…

An area-preserving diffeomorphism of an annulus has an "action function" which measures how the diffeomorphism distorts curves. The average value of the action function over the annulus is known as the Calabi invariant of the diffeomorphism, while the average value of the action function over a periodic orbit of the di…

We introduce block-tree graphs as a framework for deriving efficient algorithms on graphical models. We define block-tree graphs as a tree-structured graph where each node is a cluster of nodes such that the clusters in the graph are disjoint. This differs from junction-trees, where two clusters connected by an edge al…

We simplify matrix computations for block matrices, especially useful for covariance and correlation matrices.

Attention mechanism is a hot spot in deep learning field. Using channel attention model is an effective method for improving the performance of the convolutional neural network. Squeeze-and-Excitation block takes advantage of the channel dependence, selectively emphasizing the important channels and compressing the rel…

Proposes BMME for optimizing nonsmooth nonconvex problems with block structure.

Paper finds exotic diffeomorphisms on specific 4-manifolds.

Theta graph diffeomorphism shows nontrivial mapping class of 4-sphere.

The paper finds diffeomorphic complex intersections with distinct Hodge numbers.

Positive paths connect diffeomorphisms on contact manifolds.

Alternating Direction Method of Multipliers (ADMM) has become a widely used optimization method for convex problems, particularly in the context of data mining in which large optimization problems are often encountered. ADMM has several desirable properties, including the ability to decompose large problems into smalle…

Paper proposes ABDR for convex subspace clustering with adaptive block diagonal representation.

The paper proposes a deep learning approach to efficiently approximate diffeomorphisms for shape alignment.

Proves transitivity of real Anosov diffeomorphisms with specific properties.