Research
On-device research index

arXiv research

A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,742 papers · 148 categories

Trend · papers per month

7142128 · Feb 202019922001200920172026
48 results for momentum polytopes

We compute the sheaf of automorphisms of a multiplicity free Hamiltonian manifold over its momentum polytope and show that its higher cohomology groups vanish. Together with a theorem of Losev, arXiv:math/0612561, this implies a conjecture of Delzant: a compact multiplicity free Hamiltonian manifold is uniquely determi…

2010-02-23abs ↗pdf ↗

Consider a Hamiltonian action of a compact Lie group on a compact symplectic manifold. A theorem of Kirwan's says that the image of the momentum mapping intersects the positive Weyl chamber in a convex polytope. I present a new proof of Kirwan's theorem, which gives explicit information on how the vertices of the polyt…

1994-08-15abs ↗pdf ↗

We study polar orbitopes, i.e. convex hulls of orbits of a polar representation of a compact Lie group. The face structure is studied by means of the gradient momentum map and it is shown that every face is exposed and is again a polar orbitope. Up to conjugation the faces are completely determined by the momentum poly…

2012-06-25abs ↗pdf ↗

The study broadens the concept of cyclic polytopes to Veronese polytopes.

problem Extending the framework of cyclic polytopes to a broader class of polytopes.
method Described facial structure and combinatorial characterisation of facets via σ-parity alternating sequences.
result Established a bijective correspondence between combinatorial types of Veronese polytopes and partitions of finite sets.

The paper studies deformation spaces of Coxeter truncation polytopes.

problem Understanding the geometric properties and deformations of Coxeter truncation polytopes.
method Analyzing Coxeter truncation polytopes and their deformation spaces.
result Description of deformation spaces for Coxeter truncation polytopes of dimension d4d \geqslant 4.

In this article we study the Hofer geometry of a compact Lie group KK which acts by Hamiltonian diffeomorphisms on a symplectic manifold MM. Generalized Hofer norms on the Lie algebra of KK are introduced and analyzed with tools from group invariant convex geometry, functional and matrix analysis. Several global res…

2019-07-23abs ↗pdf ↗

Given a finite collection P of convex n-polytopes in RP^n (n>1), we consider a real projective manifold M which is obtained by gluing together the polytopes in P along their facets in such a way that the union of any two adjacent polytopes sharing a common facet is convex. We prove that the real projective structure on…

2007-05-27abs ↗pdf ↗

Given a lattice L of R^n, a polytope D is called a Delaunay polytope in L if the set of its vertices is S\cap L where S is a sphere having no lattice points in its interior. D is called perfect if the only ellipsoid in R^n that contains S\cap L is exactly S. For a vector v of the Leech lattice Λ_{24} we define Λ_{24}(v…

2009-07-04abs ↗pdf ↗

New insights into Kähler Ricci solitons and Calabi-Yau cones.

problem Understanding Kähler Ricci solitons and their relationship to Calabi-Yau cones.
method Analyzing the canonical cone of Fano manifolds and using openness of weight functions.
result The canonical cone of a product of a smooth Fano manifold and a complex projective space is a Calabi-Yau cone under certain conditions.

Polytopic Matrix Factorization models data as latent vectors from a polytope, maximizing determinant for identifiability.

problem Data decomposition with semi-structured latent vectors and polytope constraints.
method Model input data as latent vectors from a polytope, using determinant maximization for identifiability.
result Identifiability condition for polytopes with specific symmetry restrictions.

The article studies factorization structures in geometry and their applications to cones and polytopes.

problem Understanding and characterizing factorization structures in geometry.
method Comprehensive study of factorization structures, including structure theory, construction of compatible polytopes and cones, and derivation of generalised Gale's evenness condition.
result Established generalised Vandermonde identities and found examples of Delzant and rational Delzant compatible polytopes.

New methods classify hyperbolic polytopes with up to 40 facets.

problem Classifying compact hyperbolic Coxeter polytopes with specific facet counts.
method New combinatorial method via point set order types.
result Proves existence of a compact hyperbolic Coxeter 29-polytope with at least 40 facets.

Proves necessity of at least log2(n) layers to compute maximum of n numbers.

problem Computing the maximum of n numbers with ReLU neural networks.
method Uses lattice polytopes and duality with Newton polytopes to prove depth lower bounds.
result Proves that log2(n) hidden layers are necessary and sufficient.

Efficiently projects points onto polytopes, especially useful in web-scale applications.

problem Efficiently projecting points onto polytopes in large-scale applications.
method Developed a vertex-oriented incremental algorithm for polytope projection, tailored for simplex and unit-box cut polytopes.
result Majority of projections lie on vertices of polytopes, leading to significant performance improvements.

We study the Newton polytopes of determinants of square matrices defined over rings of twisted Laurent polynomials. We prove that such Newton polytopes are single polytopes (rather than formal differences of two polytopes); this result can be seen as analogous to the fact that determinants of matrices over commutative …

2018-02-20abs ↗pdf ↗

Geometric constraints help classify hyperbolic polytopes.

problem Classifying reflective anisotropic Lorentzian lattices and cocompact arithmetic hyperbolic reflection groups.
method Established geometric constraints on compact Coxeter polytopes in hyperbolic spaces.
result Geometric constraints are useful for classifying hyperbolic polytopes.

New noncompact Coxeter polytopes found in various dimensions.

problem Classifying and constructing noncompact hyperbolic Coxeter polytopes.
method Maximal-cusp density and noncompact analog of Bogachev-Douba-Raimbault's argument.
result Infinitely many pairwise incommensurable noncompact Coxeter polytopes in dimensions 4-9.

The paper classifies compact hyperbolic Coxeter polytopes and improves upper bounds.

problem Classifying compact hyperbolic Coxeter polytopes and understanding their combinatorial properties.
method Study of imes0 imes_0-products of Lannér diagrams, proving superhyperbolic properties, and analyzing Lannér subdiagrams.
result Improved upper bounds on the dimension of compact hyperbolic Coxeter polytopes.

We investigate polyhedral 2k2k-manifolds as subcomplexes of the boundary complex of a regular polytope. We call such a subcomplex {\it kk-Hamiltonian} if it contains the full kk-skeleton of the polytope. Since the case of the cube is well known and since the case of a simplex was also previously studied (these are so…

2008-09-24abs ↗pdf ↗

Real moment-angle manifolds of combinatorially equivalent simple polytopes are equivariantly diffeomorphic.

problem Uniqueness of smooth structures on real moment-angle manifolds.
method Arguments from calculus applied to results from complex moment-angle manifolds.
result Real moment-angle manifolds of combinatorially equivalent simple polytopes are equivariantly diffeomorphic.

We study the space of generalized translation invariant valuations on a finite-dimensional vector space and construct a partial convolution which extends the convolution of smooth translation invariant valuations. Our main theorem is that McMullen's polytope algebra is a subalgebra of the (partial) convolution algebra …

2014-06-17abs ↗pdf ↗

We show that the Grothendieck group associated to integral polytopes in Rn\mathbb{R}^n is free-abelian by providing an explicit basis. Moreover, we identify the involution on this polytope group given by reflection about the origin as a sum of Euler characteristic type. We also compute the kernel of the norm map sendin…

2016-05-04abs ↗pdf ↗