arXiv research

Proves homological inequality for cycles in Hadamard spaces of asymptotic rank 2.

Sharp isoperimetric inequalities for Neumann eigenvalues in symmetric spaces.

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…

Maps from rational homology solid tori yield rank inequalities in Heegaard Floer homology.

Develops new oracle inequalities for Gaussian ranking estimators.

New inequalities generalize Li's theorem on mixed Hodge structures.

Study proves inequality for eigenvalues in symmetric spaces.

We describe the set of possible vector valued side lengths of n-gons in thick Euclidean buildings of rank 2. This set is determined by a finite set of homogeneous linear inequalities, which we call the generalized triangle inequalities. These inequalities are given in terms of the combinatorics of the spherical Coxeter…

The paper proves concentration inequalities for two-sample rank processes and applies them to ranking performance criteria.

Study on submanifolds with specific nullity ranks, proving inequalities between nullity ranks.

We use generalised cross--ratios to prove the Ptolemaean inequality and the Theorem of Ptolemaeus in the setting of the boundary of symmetric Riemannian spaces of rank 1 and of negative curvature.

The free factor complex of rank 4+ fails a combinatorial isoperimetric inequality.

The paper analyzes tensor recovery from symmetric rank-one measurements using information theory.

Let $\widetilde{K}$ be a 2-periodic knot in $S^3$ with quotient $K$. We prove a rank inequality between the knot Floer homology of $\widetilde{K}$ and the knot Floer homology of $K$ using a spectral sequence of Hendricks, Lipshitz and Sarkar. We also conjecture a filtered refinement of this inequality, for which we giv…

Study shows rank of knot Floer homology detects Hopf links and classifies second smallest links.

Linear inequality found for certain curved spaces.

For a 2-periodic link $\tilde L$ in the thickened annulus and its quotient link $L$, we exhibit a spectral sequence with $E^1 \cong AKh(\tilde L) \otimes_{\mathbb{F}_2} \mathbb{F}_2[θ, θ^{-1}] \rightrightarrows E^\infty \cong AKh(L) \otimes_{\mathbb{F}_2} \mathbb{F}_2[θ, θ^{-1}].$ This spectral sequence splits along qu…

We investigate properties of estimators obtained by minimization of U-processes with the Lasso penalty in high-dimensional settings. Our attention is focused on the ranking problem that is popular in machine learning. It is related to guessing the ordering between objects on the basis of their observed predictors. We p…

Paper tackles underranking in group-fair ranking systems, proving a trade-off and presenting an algorithm.

Paper proves geodesic ball maximizes second Robin eigenvalue in non-compact symmetric spaces.

Paper proves eigenvalue inequality for Hopf-symmetric domains.

The study establishes uncertainty principles on harmonic manifolds of rank one.

In this note, we derive a new logarithmic Sobolev inequality for the heat kernel on the Heisenberg group. The proof is inspired from the historical method of Leonard Gross with the Central Limit Theorem for a random walk. Here the non commutative nature of the increments produces a new gradient which naturally involves…

Study shows inequality in Floer homologies for 3-manifold covers.

Paper presents a low-cost algorithm for bipartite ranking with improved sample size requirements.

The study shows a new upper bound on the homology rank of hyperbolic 3-manifolds.

A number of statistical estimation problems can be addressed by semidefinite programs (SDP). While SDPs are solvable in polynomial time using interior point methods, in practice generic SDP solvers do not scale well to high-dimensional problems. In order to cope with this problem, Burer and Monteiro proposed a non-conv…

New proofs for curvature problems using a viscosity approach.

New conditions ensure Dantzig-Wolfe relaxation matches rank-constrained optimization problems.

This paper establishes inequalities on quaternionic hyperbolic spaces and the Cayley hyperbolic plane.

Generalizes Toledo invariant to singular klt varieties, proving Milnor-Wood inequality.

Let $M$ be a compact connected orientable Seifert manifold with hyperbolic orbifold $B_M$, and $f_π: π_1(M)\rightarrowπ_1(M)$ be an automorphism induced by an orientation-reversing homeomorphism $f$ of $M$. We give a bound on the rank of the fixed subgroup of $f_π$, namely, $\rank\fix(f_π)<2\rank π_1(M)$, which is simi…

Low-rank matrix recovery has found many applications in science and engineering such as machine learning, signal processing, collaborative filtering, system identification, and Euclidean embedding. But the low-rank matrix recovery problem is an NP hard problem and thus challenging. A commonly used heuristic approach is…

In constant curvatures spaces, there are a lot of characterizations of geodesic balls as optimal domain for shape optimization problems. Although it is natural to expect similar characterizations in rank one symmetric spaces, very few is known in this setting. In this paper we prove that, in a non-compact rank one symm…

We study the problem of prediction for evolving graph data. We formulate the problem as the minimization of a convex objective encouraging sparsity and low-rank of the solution, that reflect natural graph properties. The convex formulation allows to obtain oracle inequalities and efficient solvers. We provide empirical…

Given a knot K in S^3, let Σ(K) be the double branched cover of S^3 over K. We show there is a spectral sequence whose E^1 page is (\hat{HFK}(Σ(K), K) \otimes V^{n-1}) \otimes \mathbb Z_2((q)), for V a \mathbb Z_2-vector space of dimension two, and whose E^{\infty} page is isomorphic to (\hat{HFK}(S^3, K) \otimes V^{n-…

Establishes a rank inequality between knot Floer homologies of freely 2-periodic knots and their quotients.

Refines online learning to rank algorithm with tighter bounds.

A well-known conjecture of Rasmussen states that for any knot $K$ in $S^{3}$, the rank of the reduced Khovanov homology of $K$ is greater than or equal to the rank of the reduced knot Floer homology of $K$. This rank inequality is supposed to arise as the result of a spectral sequence from Khovanov homology to knot Flo…

Generalizes Cheeger inequality to Carnot-Carathéodory spaces.

We introduce the notions of categorical systoles and categorical volumes of Bridgeland stability conditions on triangulated categories. We prove that for any projective K3 surface, there exists a constant C depending only on the rank and discriminant of its Picard group, such that $$\mathrm{sys}(σ)^2\leq C\cdot\mathrm{…

New method learns low-dimensional representations of nonlinear time series without supervision.

We solve robust regression and matrix completion problems with sparse and low-rank models.

We study a new class of rank two sub-Riemannian manifolds encompassing Riemannian manifolds, CR manifolds with vanishing Webster-Tanaka torsion, orthonormal bundles over Riemannian manifolds, and graded nilpotent Lie groups of step two. These manifolds admit a canonical horizontal connection and a canonical sub-Laplaci…

This note quantifies, via a sharp inequality, an interplay between (a) the characteristic rank of a vector bundle over a topological space X, (b) the Z/2Z-Betti numbers of X, and (c) sums of the numbers of certain partitions of integers. In a particular context, (c) is transformed into a sum of the readily calculable B…

This paper improves entropy bounds for ranking time-series complexity.

This work establishes always-valid risk bounds for online matrix completion.

Study shows knot grading properties in specific spaces.