arXiv research

Study curvature operators with sectional curvature bounds using convex algebraic geometry.

Paper surveys balanced metrics and proves a geodesic convexity result.

Paper proves optimal decomposition for matrix fields, reducing convex integration steps.

We investigate subgroups of SL (n,Z) which preserve an open nondegenerate convex cone in real n-space and admit in that cone as fundamental domain a polyhedral cone of which some faces are allowed to lie on the boundary. Examples are arithmetic groups acting on selfdual cones, Weyl groups of certain Kac-Moody algebras …

A polarity of a projective plane is a map, often assumed to be involutive, mapping a generic point to a generic line and reciprocally. The most classical polarity is the polarity with respect to a conic, but other exist: the harmonic polarity with respect to a triangle, the polarities with respect to high-degree algebr…

Tropical geometry and weighted lattices improve curve and surface fitting.

TML package uses tropical geometry for machine learning tasks.

We establish a natural and geometric 1-1 correspondence between projective toric varieties of dimension $n$ and horofunction compactifications of $\mathbb{R}^n$ with respect to rational polyhedral norms. For this purpose, we explain a topological model of toric varieties. Consequently, toric varieties in algebraic geom…

Study circumcenters in Finsler unitary groups with optimal convexity bounds.

We give in explicit form the principal kinematic formula for the action of the affine unitary group on $\C^n$, together with a straightforward algebraic method for computing the full array of unitary kinematic formulas, expressed in terms of certain convex valuations introduced, essentially, by H. Tasaki. We introduce …

In this paper we construct a compactification for the parameter space of convex projective structures on a fixed n-manifold M. This parameter space is a closed semi-algebraic subset of the variety of characters of representations of the fundamental group of M in SL_{n+1}(R). The boundary is the inverse limit of an inve…

The Hilbert manifold $Σ$ consisting of positive invertible (unitized) Hilbert-Schmidt operators has a rich structure and geometry. The geometry of unitary orbits $Ω\subset Σ$ is studied from the topological and metric viewpoints: we seek for conditions that ensure the existence of a smooth local structure for the set $…

In symmetric cones, a non-empty locus satisfies the WDVV equation, generalizing previous results.

After observing that the well-known convexity theorems of symplectic geometry also hold for compact contact manifolds with an effective action of a torus whose Reeb vector field corresponds to an element of the Lie algebra of the torus, we use this fact together with a recent symplectic orbifold version of Delzant's th…

In this paper we study the metric geometry of the space $Σ$ of positive invertible elements of a von Neumann algebra ${\mathcal A}$ with a finite, normal and faithful tracial state $τ$. The trace induces an incomplete Riemannian metric $<x,y>_a=τ(ya^{-1}xa^{-1})$, and though the techniques involved are quite different,…

We show that associating the Euclidean cell decomposition due to Cooper and Long to each point of the moduli space of framed strictly convex real projective structures of finite volume on the once-punctured torus gives this moduli space a natural cell decomposition. The proof makes use of coordinates due to Fock and Go…

An Einstein nilradical is a nilpotent Lie algebra, which can be the nilradical of a metric Einstein solvable Lie algebra. The classification of Riemannian Einstein solvmanifolds (possibly, of all noncompact homogeneous Einstein spaces) can be reduced to determining, which nilpotent Lie algebras are Einstein nilradicals…

We show that a pseudo-Anosov map on a boundary component of an irreducible 3-manifold has a power that partially extends to the interior if and only if its (un)stable lamination is a projective limit of meridians. The proof is through 3-dimensional hyperbolic geometry, and involves an investigation of algebraic limits …

Surveying probabilistic real algebraic geometry.

On the predual of a von Neumann algebra, we define a differentiable manifold structure and affine connections by embeddings into non-commutative L_p-spaces. Using the geometry of uniformly convex Banach spaces and duality of the L_p and L_q spaces for 1/p+1/q=1, we show that we can introduce the α-divergence, for αin (…

New algebraic-geometry method for Ribaucour transformations.

Survey explores interactions between convex and complex geometry.

Machine learning applied to algebraic geometry for physics problems.

Randomized Geometric Algebra for Convex Neural Networks Optimizes Transfer Learning.

High-order Klein geometries constructed using Lie algebras.

A survey on recent developments in (algebraic) integral geometry is given. The main focus lies on algebraic structures on the space of translation invariant valuations and applications in integral geometry.

The paper examines smoothness in diffusion algebra.

Study on extremals in sub-Lorentzian geometry defined by antinorm.

Necessary and sufficient conditions for the exponentiation of finite-dimensional real Lie algebras of linear operators on complete Hausdorff locally convex spaces are obtained, focused on the equicontinuous case - in particular, necessary conditions for exponentiation to compact Lie groups are established. Applications…

Non-lorentzian geometry reviewed, including Lie algebras and Klein geometries.

New geometric transitions studied via real algebra degenerations.

Uniform convexity in divisible domains leads to hyperbolic geometry.

Let $Λ$ be a finite abelian group. A dynamical system with transformation group $Λ$ is a triple $(A,Λ,α)$, consisting of a unital locally convex algebra $A$, the finite abelian group $Λ$ and a group homomorphism $α:Λ\rightarrow\Aut(A)$, which induces an action of $Λ$ on $A$. In this paper we present a new, geometricall…

Surveying recent work on Kähler metrics and algebraic variety stability.

Algebraic geometry replaces manifolds in differential geometry.

Paper constructs observables using multisymplectic geometry and algebraic methods.

We exploit the spinor description of four-dimensional Walker geometry, and conformal rescalings of such, to describe the local geometry of four-dimensional neutral geometries with algebraically degenerate self-dual Weyl curvature and an integrable distribution of alpha-planes (algebraically special real alpha-geometry)…

The abstract discusses how Kähler-Einstein metrics relate to algebraic geometry.

This paper formalizes the h-principle and sphere eversion in differential topology.

Convex cores found for group actions on median spaces.

Convexity properties are preserved under radial transformations in hyperbolic and spherical geometries.

Authors discuss complex and non-Archimedean geometry, proving a conjecture.

New algebra invariant distinguishes Legendrian knots in convex surfaces.

Survey on algebraic K- and L-theory conjecture.

We introduce a class of combinatorial hypersurfaces in the complex projective space. They are submanifolds of codimension~2 in $\C P^n$ and are topologically "glued" out of algebraic hypersurfaces in $(\C^*)^n$. Our construction can be viewed as a version of the Viro gluing theorem, relating topology of algebraic hyper…

The paper connects Kähler-Ricci shrinkers to Fano fibrations in algebraic geometry.

Paper extends algebraic geometry results to hyperbolic link complements.

Novel analysis of neural networks using geometric algebra and convex optimization.