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We construct toric manifolds of complex dimension $\geq 4$, whose orbit spaces by the action of the compact torus are not homeomorphic to simple polytopes (as manifolds with corners). These provide the first known examples of toric…

Algebraic Geometry · Mathematics 2014-11-26 Yusuke Suyama

We prove that if the associated fourth order tensor of a quadratic form has a linear elastic cubic symmetry then it is quasiconvex if and only if it is polyconvex, i.e. a sum of convex and null-Lagrangian quadratic forms. We prove that…

Analysis of PDEs · Mathematics 2016-11-26 Davit Harutyunyan , Graeme Walter Milton

This paper is about the logarithmic limit sets of real semi-algebraic sets, and, more generally, about the logarithmic limit sets of sets definable in an o-minimal, polynomially bounded structure. We prove that most of the properties of the…

Algebraic Geometry · Mathematics 2018-09-25 Daniele Alessandrini

We introduce a natural notion of quaternionic map between almost quaternionic manifolds and we prove the following, for maps of rank at least one: 1) A map between quaternionic manifolds endowed with the integrable almost twistorial…

Differential Geometry · Mathematics 2015-05-13 S. Ianus , S. Marchiafava , L. Ornea , R. Pantilie

To define an explicit regions without zeros of $\mathop{\mathcal R}(s)$, in a previous paper we obtained an approximation to $\mathop{\mathcal R}(s)$ of type $f(s)(1+U)$ with $|U|< 1$. But this $U$ do not tend to zero when $t\to+\infty$. In…

Number Theory · Mathematics 2024-06-11 Juan Arias de Reyna

We prove the existence of manifolds with almost maximal volume entropy which are not hyperbolic.

Differential Geometry · Mathematics 2017-03-01 Viktor Schroeder , Hemangi Shah

In this paper we study a $k$-dimensional analytic subvariety of the complex algebraic torus. We show that if its logarithmic limit set is a finite rational $(k-1)$-dimensional spherical polyhedron, then each irreducible component of the…

Algebraic Geometry · Mathematics 2014-07-25 Farid Madani , Lamine Nisse , Mounir Nisse

We prove that the rank-one convex hull of finitely many $2\times 2$ triangular matrices is a semialgebraic set, defined by linear and quadratic polynomials. We present explicit constructions for five-point configurations and offer evidence…

Metric Geometry · Mathematics 2025-09-10 Chiara Meroni , Bogdan Raita

Almost toric manifolds form a class of singular Lagrangian fibered symplectic manifolds that is a natural generalization of toric manifolds. Notable examples include the K3 surface, the phase space of the spherical pendulum and rational…

Symplectic Geometry · Mathematics 2007-05-23 Naichung Conan Leung , Margaret Symington

We study non-archimedean $\mu$-entropy for toric variety as a further exploration of $\mu$K-stability. We show the existence of optimizer of toric non-archimedean $\mu^\lambda$-entropy for $\lambda \in \mathbb{R}$ and the uniqueness for…

Differential Geometry · Mathematics 2023-03-17 Eiji Inoue

Tropical algebraic geometry is the geometry of the tropical semiring $(\mathbb{R},\min,+)$. Its objects are polyhedral cell complexes which behave like complex algebraic varieties. We give an introduction to this theory, with an emphasis on…

Algebraic Geometry · Mathematics 2007-05-23 Jürgen Richter-Gebert , Bernd Sturmfels , Thorsten Theobald

We define a category of motives for semi-algebraic spaces and show that it is trivial. This implies that there is no good extension of algebraic de Rham cohomology to semi-algebraic spaces compatible with the period isomorphism.

Algebraic Geometry · Mathematics 2020-07-21 Annette Huber

We combine some known results and techniques with new ones to show that there exists a non-algebraic, multi-linear matroid. This answers an open question by Matus (Discrete Mathematics 1999), and an open question by Pendavingh and van Zwam…

Combinatorics · Mathematics 2016-07-01 Aner Ben-Efraim

Semi-Equivelar maps are generalizations of Archimedean solids to the surfaces other than 2-sphere. In earlier work a complete classification of semi-equivelar map of type $(3^5, 4)$ on the surface of Euler characteristic -1 was given. In…

Geometric Topology · Mathematics 2013-10-22 Ashish K Upadhyay , Anand K Tiwari

In the case of a linear symplectic map A of the 2d-torus, semiclassical measures are A-invariant probability measures associated to sequences of high energy quantum states. Our main result is an explicit lower bound on the entropy of any…

Dynamical Systems · Mathematics 2011-09-09 Gabriel Riviere

In this work it is shown that certain interesting types of quasi-orthogonal system of subalgebras (whose existence cannot be ruled out by the trivial necessary conditions) cannot exist. In particular, it is proved that there is no…

Mathematical Physics · Physics 2010-02-02 Mihály Weiner

We prove a version of the Thom Isotopy Theorem for nonproper semialgebraic maps $f\colon X\rightarrow \mathbb{R}^m$, where $X \subset\mathbb{R}^n$ is a semialgebraic set and $f$ is the restriction to $X$ of a smooth semialgebraic map…

Differential Geometry · Mathematics 2024-04-30 Luis Renato Gonçalves Dias , Giovanny Snaider Barrera Ramos

We give an elementary argument for the well known fact that the endomorphism algebra $End_Q(A)$ of a simple complex abelian surface $A$ can neither be an imaginary quadratic field nor a definite quaternion algebra. Another consequence of…

Algebraic Geometry · Mathematics 2007-05-23 Wolfgang M. Ruppert

The main purpose of this paper is to prove the mean ergodic theorem for nonexpansive mappings and semigroups in locally compact Hadamard spaces, including finite dimensional Hadamard manifolds. The main tool for proving ergodic convergence…

Functional Analysis · Mathematics 2021-05-07 Hadi Khatibzadeh , Hadi Pouladi

In this paper we deal with the classical question of existence of polynomial in momenta integrals for geodesic flows on the 2-torus. For the quasi-linear system on coefficients of the polynomial integral we consider the region (so called…

Differential Geometry · Mathematics 2013-04-01 Michael , Bialy , Andrey Mironov
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