arXiv research

Paper proves Fourier transform for valuations, simplifying previous work.

Study generalizes finiteness theorem using Lie theory.

Alesker has introduced the space $\mathcal V^\infty(M)$ of {\it smooth valuations} on a smooth manifold $M$, and shown that it admits a natural commutative multiplication. Although Alesker's original construction is highly technical, from a moral perspective this product is simply an artifact of the operation of inters…

New proof of Alesker's Irreducibility Theorem using localization techniques.

The Weyl tube theorem is extended to Kähler manifolds.

S. Alesker has shown that if $G$ is a compact subgroup of O(n) acting transitively on the unit sphere $S^{n-1}$ then the vector space $Val^G$ of continuous, translation-invariant, $G$-invariant convex valuations on $R^n$ has the structure of a finite dimensional graded algebra over $R$ satisfying Poincare duality. We s…

Paper refines Alesker-Bernig-Schuster theorem, proving Hodge-Riemann relations for Euclidean balls.

Alternative proof of a theorem using parabolic Monge-Ampère equation in HKT geometry.

Solves a conjecture about hyperKähler manifolds using quaternionic Monge-Ampère equation.

Researchers find a way to estimate potential functions for quaternionic metrics.

Proves hard Lefschetz theorem and Hodge-Riemann relations for convex valuations.

New proof confirms operations on constructible functions match theory.

We prove the $C^0$ estimate for the quaternionic Monge-Ampère equation on compact hyperKähler with torsion manifolds. Our goal is to provide a simpler proof than the one presented by Alesker and Shelukhin.

A famous theorem of Weyl states that if $M$ is a compact submanifold of euclidean space, then the volumes of small tubes about $M$ are given by a polynomial in the radius $r$, with coefficients that are expressible as integrals of certain scalar invariants of the curvature tensor of $M$ with respect to the induced metr…

Developed new Crofton formulas for pseudo-Riemannian spaces.

We prove new kinematic formulas for tensor valuations and simplify previously known Crofton formulas by using the recently developed algebraic theory of translation invariant valuations. The heart of the paper is the computation of the Alesker-Fourier transform on the large class of spherical valuations, which is achie…

Proves Euler characteristic of collapsing Alexandrov spaces.

New Orlicz Brunn-Minkowski inequalities are established for rigid motion compatible Minkowski valuations of arbitrary degree. These extend classical log-concavity properties of intrinsic volumes and generalize seminal results of Lutwak and others. Two different approaches which refine previously employed techniques are…

Solves a specific Calabi conjecture on special nilmanifolds.

This is a revised version of the notes from the week-long course I gave at the Centre de Recerca Matematica, Barcelona, in September of 2010. The aim is to give a working overview of recent methods and results in "Blaschkean integral geometry" (i.e. the subject revolving around the kinematic formulas of Blaschke) in th…

Solves long-time solutions for a specific equation on hyperkähler manifolds.

The Alesker-Poincare pairing for smooth valuations on manifolds is expressed in terms of the Rumin differential operator acting on the cosphere-bundle. It is shown that the derivation operator, the signature operator and the Laplace operator acting on smooth valuations are formally self-adjoint with respect to this pai…

We show that the natural "convolution" on the space of smooth, even, translation-invariant convex valuations on a euclidean space $V$, obtained by intertwining the product and the duality transform of S. Alesker, may be expressed in terms of Minkowski sum. Furthermore the resulting product extends naturally to odd valu…

We study the asymptotic properties of the conormal cycle of nodal sets associated to a random superposition of eigenfunctions of the Laplacian on a smooth compact Riemannian manifold without boundary. In the case where the dimension is odd, we show that the expectation of the corresponding current of integration equidi…

Study elliptic equations on hyperhermitian manifolds with flat hyperkähler metric.

Study fully nonlinear elliptic equations on compact hyperhermitian manifolds.

Study convolution of invariant valuations on Lie groups.

A Minkowski class is a closed subset of the space of convex bodies in Euclidean space Rn which is closed under Minkowski addition and non-negative dilatations. A convex body in Rn is universal if the expansion of its support function in spherical harmonics contains non-zero harmonics of all orders. If K is universal, t…

Sharp $C^0$ bound for quaternionic Monge-Ampere on hyperhermitian manifolds.

Generalizing Weyl's tube formula and building on Chern's work, Alesker reinterpreted the Lipschitz-Killing curvature integrals as a family of valuations (finitely-additive measures with good analytic properties), attached canonically to any Riemannian manifold, which is universal with respect to isometric embeddings. I…

We show how Alesker's theory of valuations on manifolds gives rise to an algebraic picture of the integral geometry of any Riemannian isotropic space. We then apply this method to give a thorough account of the integral geometry of the complex space forms, i.e. complex projective space, complex hyperbolic space and com…

Proves Hodge-Riemann relations for mixed valuations and strengthens geometric inequalities.

Isomorphic cosymplectomorphism groups imply diffeomorphic manifolds.

Proves a Thom isomorphism for foliated differential forms.

New knot quandles distinguish ribbon knots with isomorphic groups.

Geometric duality connects graph isomorphism and knot equivalence.

In this paper, we introduce the notion of Reidemeister torsion for quasi-isomorphisms of based chain complexes over a field. We call a chain map a quasi-isomorphism if its induced homomorphism between homology is an isomorphism. Our notion of torsion generalizes the torsion of acyclic based chain complexes, and is a ch…

The paper explores isomorphisms on isoparametric hypersurfaces in spheres, leading to new geometric structures.

We construct examples of knots that have isomorphic nth-order Alexander modules, but non-isomorphic nth-order linking forms, showing that the linking forms provide more information than the modules alone. This generalizes work of Trotter, who found examples of knots that have isomorphic classical Alexander modules, but…

Proves regularity of isomorphisms between hyperbolic 3-manifolds.

We classify connected Lie groups which are locally isomorphic to generalized Heisenberg groups. For a given generalized Heisenberg group $N$, there is a one-to-one correspondence between the set of isomorphism classes of connected Lie groups which are locally isomorphic to $N$ and a union of certain quotients of noncom…

Non-isomorphic groups with similar profinite completions found.

Paper tackles NP-complete subgraph isomorphism counting problem.

Paper solves isomorphism problem for specific Baumslag-Solitar groups.

We consider the notion of stable isomorphism of bundle gerbes. It has the consequence that the stable isomorphism classes of bundle gerbes over a manifold M are in bijective correspondence with H^3(M, Z). Stable isomorphism sheds light on the local theory of bundle gerbes and enables us to develop a classifying theory …

New benchmarks improve model performance by accounting for isomorphism classes in multi-relational datasets.

This is the fourth of five papers that construct an isomorphism between the Seiberg-Witten Floer homology and the Heegaard Floer homology of a given compact, oriented 3-manifold. The isomorphism is given as a composition of three isomorphisms; the first of these relates a version of embedded contact homology on an an a…

Undecidability proved for DG algebras problems.