Publications associées à Polytope régulier

Anomalous and Chern topological waves in hyperbolic networks

Romain Christophe Rémy Fleury, Haoye Qin, Aleksi Antoine Bossart, Zhechen Zhang

Hyperbolic lattices are a new type of synthetic materials based on regular tessellations in non-Euclidean spaces with constant negative curvature. While so far, there has been several theoretical investigations of hyperbolic topological media, experimental ...

Nature Research2024

Grand canonical Brownian dynamics simulations of adsorption and self-assembly of SAS-6 rings on a surface

Pierre Gönczy, Niccolo Banterle

The Spindle Assembly Abnormal Protein 6 (SAS-6) forms dimers, which then self-assemble into rings that are critical for the nine-fold symmetry of the centriole organelle. It has recently been shown experimentally that the self-assembly of SAS-6 rings is st ...

AIP Publishing2023

An unrefinement algorithm for planar THB-spline parameterizations

Annalisa Buffa

Unrefinement is a tool that allows to perform faster numerical simulations by controlling the level of precision in the specified area. We introduce an algorithm that creates a coarser geometry from an initial regular geometry, which is represented with re ...

ELSEVIER2022

Synthesis and properties of heterostructures in nanowires and 2-D materials

Akshay Balgarkashi

Modern solid-state devices were made possible by the discovery of semiconductor heterostructures. Heterostructures offer the ability to fabricate low-dimensional nanostructures such as quantum dots which can restrain carriers in all three-directions. Quant ...

EPFL2022

Collapse-invariant properties of spaces equipped with signals or directions

Stefania Ebli

Collapsing cell complexes was first introduced in the 1930's as a way to deform a space into a topological-equivalent subspace with a sequence of elementary moves. Recently, discrete Morse theory techniques provided an efficient way to construct deformatio ...

EPFL2022

Free Boundary Regularity for Almost Every Solution to the Signorini Problem

Xavier Fernandez-Real Girona

We investigate the regularity of the free boundary for the Signorini problem in Rn+1. It is known that regular points are (n−1)-dimensional and C∞. However, even for C∞ obstacles φ, the set of non-regular (or degenerate) points could be very large—e.g. wit ...

2021

Generic vanishing in characteristic p > 0 and the geometry of theta divisors

Zsolt Patakfalvi

In this paper, we prove a strengthening of the generic vanishing result in characteristic p > 0 given in Hacon and Patakfalvi (Am J Math 138(4):963-998, 2016). As a consequence of this result, we show that irreducible Theta divisors are strongly F-regular ...

SPRINGER INTERNATIONAL PUBLISHING AG2022

On the Volume of the John-Lowner Ellipsoid

Grigory Ivanov

We find an optimal upper bound on the volume of the John ellipsoid of a k-dimensional section of the n-dimensional cube, and an optimal lower bound on the volume of the Lowner ellipsoid of a projection of the n-dimensional cross-polytope onto a k-dimension ...

SPRINGER2020

Capture zone models of a multi-well system in aquifers bounded with regular and irregular inflow boundaries

David Andrew Barry, Setareh Nagheli

Being bounded by hydrological (inflow and barrier) boundaries, natural aquifers have regular/irregular shapes. Here, we consider aquifers bounded by segmental inflow (variable head) boundaries in which water is extracted/injected by a multi-well system. St ...

2020

Facet-driven formation of axial and radial In(Ga)As clusters in GaAs nanowires

Anna Fontcuberta i Morral, Lucas Güniat, Santhanu Panikar Ramanandan, Didem Dede, Martin George Friedl, Jean-Baptiste Leran, Wonjong Kim, Nicolas Tappy, Akshay Balgarkashi

Embedding quantum dots in nanowires (NWs) constitutes one promising building block for quantum photonic technologies. Earlier attempts to grow InAs quantum dots on GaAs nanowires were based on the Stranski-Krastanov growth mechanism. Here, we propose a nov ...

2020

New Results in Integer and Lattice Programming

Christoph Hunkenschröder

An integer program (IP) is a problem of the form

\min \{f(x) : \, Ax = b, \ l \leq x \leq u, \ x \in \Z^n\}

, where

A \in \Z^{m \times n}

,

b \in \Z^m

,

l,u \in \Z^n

, and

f: \Z^n \rightarrow \Z

is a separable convex objective function. The problem o ...

EPFL2020

Tropical Ehrhart Theory and Tropical Volume

Matthias Schymura, Georg Peter Loho

We introduce a novel intrinsic volume concept in tropical geometry. This is achieved by developing the foundations of a tropical analog of lattice point counting in polytopes. We exhibit the basic properties and compare it to existing measures. Our exposit ...

2019

Extended Formulations from Communication Protocols in Output-Efficient Time

Yuri Faenza, Manuel Francesco Aprile

Deterministic protocols are well-known tools to obtain extended formulations, with many applications to polytopes arising in combinatorial optimization. Although constructive, those tools are not output-efficient, since the time needed to produce the exten ...

SPRINGER INTERNATIONAL PUBLISHING AG2019

On 2-Level Polytopes Arising In Combinatorial Settings

Yuri Faenza, Manuel Francesco Aprile, Alfonso Bolívar Cevallos Manzano

2-level polytopes naturally appear in several areas of pure and applied mathematics, including combinatorial optimization, polyhedral combinatorics, communication complexity, and statistics. In this paper, we present a study of some 2-level polytopes arisi ...

SIAM Publications2018

On some problems related to 2-level polytopes

Manuel Francesco Aprile

In this thesis we investigate a number of problems related to 2-level polytopes, in particular from the point of view of the combinatorial structure and the extension complexity. 2-level polytopes were introduced as a generalization of stable set polytopes ...

EPFL2018

On the reverse isodiametric problem and Dvoretzky-Rogers-type volume bounds

Matthias Schymura

The isodiametric inequality states that the Euclidean ball maximizes the volume among all convex bodies of a given diameter. We are motivated by a conjecture of Makai Jr. on the reverse question: Every convex body has a linear image whose isodiametric quot ...

2018

Integrative approach to analyze the proximal region of the Trichonympha agilis centriole

Veronika Nemcíková Villímová

The centrosome, the major microtubule organizing center in animal cells, is composed of two orthogonally arranged centrioles and surrounding pericentriolar material. Centrioles are evolutionary conserved organelles characterized by a nine-fold symmetry of ...

EPFL2018

Non-Normal Very Ample Polytopes - Constructions and Examples

Michal Lason

We answer several questions posed by Beck, Cox, Delgado, Gubeladze, Haase, Hibi, Higashitani, and Maclagan in [Cox et al. 14, Question 3.5 (1),(2), Question 3.6], [Beck et al. 15, Conjecture 3.5(a),(b)], and [Hasse et al. 07, Open question 3 (a),(b) p. 231 ...

Taylor & Francis Inc2017

A Non-Stationary Subdivision Scheme for the Construction of Deformable Models with Sphere-Like Topology

Michaël Unser, Daniel Andreas Schmitter, Anaïs Laure Marie-Thérèse Badoual

We present an affine-invariant non-stationary subdivision scheme for the recursive refinement of any triangular mesh that is regular or has extraordinary vertices of valence 4. In particular, when applied to an arbitrary convex octahedron, it produces a $ ...

2017

Extension complexity of stable set polytopes of bipartite graphs

Yuri Faenza, Manuel Francesco Aprile

The extension complexity xc(P) of a polytope P is the minimum number of facets of a polytope that affinely projects to P. Let G be a bipartite graph with n vertices, m edges, and no isolated vertices. Let STAB(G) be the convex hull of the stable sets of G. ...

Springer2017