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We study geometric inequalities for the circumradius and diameter with respect to general gauges, partly also involving the inradius and the Minkowski asymmetry. There are a number of options for defining the diameter of a convex body that…

Metric Geometry · Mathematics 2025-12-03 René Brandenberg , Mia Runge

For closed and oriented hyperbolic surfaces, a formula of Witten establishes an equality between two volume forms on the space of representations of the surface in a semisimple Lie group. One of the forms is a Reidemeister torsion, the…

Geometric Topology · Mathematics 2020-10-28 Michael Heusener , Joan Porti

Let M=P(E) be a ruled surface. We introduce metrics of finite volume on M whose singularities are parametrized by a parabolic structure over E. Then, we generalise results of Burns--de Bartolomeis and LeBrun, by showing that the existence…

Differential Geometry · Mathematics 2016-09-07 Yann Rollin

We prove a generalized isoperimetric inequality for a domain diffeomorphic to a sphere that replaces filling volume with $k$-dilation. Suppose $U$ is an open set in $\mathbb{R}^n$ diffeomorphic to a Euclidean $n$-ball. We show that in…

Differential Geometry · Mathematics 2022-12-29 Elia Portnoy

Modern applications in quantum computation and quantum communication require the precise characterization of quantum states and quantum channels. In practice, this means that one has to determine the quantum capacity of a physical system in…

Quantum Physics · Physics 2016-04-04 D. Bruns , J. Sperling , S. Scheel

In this work we design a specific simulation tool for quantum channels which is based on the use of a control system. This allows us to simulate an average quantum channel which is expressed in terms of an ensemble of channels, even when…

Quantum Physics · Physics 2018-12-19 Stefano Pirandola , Riccardo Laurenza , Leonardo Banchi

In this article we consider flagged extensions of convex combination of quantum channels, and find general sufficient conditions for the degradability of the flagged extension. An immediate application is a bound on the quantum $Q$ and…

Quantum Physics · Physics 2022-02-09 Farzad Kianvash , Marco Fanizza , Vittorio Giovannetti

We generalize an inequality of E. Heintze and H. Karcher [8] for the volume of tubes around minimal submanifolds to an inequality based on integral bounds for $k$-Ricci curvature. Even in the case of a pointwise bound, this generalizes the…

Differential Geometry · Mathematics 2018-10-05 Yousef K. Chahine

A new algebraic Cayley graph is constructed using finite fields. Its connectedness and diameter bound are studied via Weil's estimate for character sums. These graphs provide a new source of expander graphs, extending classical results of…

Combinatorics · Mathematics 2013-04-09 Mei Lu , Daqing Wan , Li-Ping Wang , Xiao-Dong Zhang

Given a completely positive map, we introduce a set of algebras that we refer to as its generalized multiplicative domains. These algebras are generalizations of the traditional multiplicative domain of a completely positive map and we…

Quantum Physics · Physics 2015-03-17 Nathaniel Johnston , David W. Kribs

This article analyzes the algebraic structure of the set of all quantum channels and its subset consisting of quantum channels that have Holevo representation. The regularity of these semigroups under composition of mappings is analyzed. It…

Quantum Physics · Physics 2025-05-13 M. N. N. Namboodiri

We study geodesics in generalized Wallach spaces which are expressed as orbits of products of three exponential terms. These are homogeneous spaces $M=G/K$ whose isotropy representation decomposes into a direct sum of three submodules…

Differential Geometry · Mathematics 2015-11-26 Andreas Arvanitoyeorgos , Nikolaos Panagiotis Souris

We compute the depth and (give bounds for) the regularity of generalized binomial edge ideals associated with generalized block graphs.

Commutative Algebra · Mathematics 2017-09-25 Faryal Chaudhry , Rida Irfan

In this note, we show that the normalized local volume of a non-closed point can be expressed in terms of the normalized local volumes of closed points.

Algebraic Geometry · Mathematics 2026-05-15 Donghyeon Kim

A relatively fast algorithm for evaluating Weil-Petersson volumes of moduli spaces of complex algebraic curves is proposed. On the basis of numerical data, a conjectural large genus asymptotics of the Weil-Petersson volumes is computed.…

Algebraic Geometry · Mathematics 2020-12-08 Peter Zograf

We present a wave generalization of the classic Schwarzschild method for constructing self-consistent halos -- such a halo consists of a suitable superposition of waves instead of particle orbits, chosen to yield a desired mean density…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-09 Tomer D. Yavetz , Xinyu Li , Lam Hui

We use ending laminations for Weil-Petersson geodesics to establish that bounded geometry is equivalent to bounded combinatorics for Weil-Petersson geodesic segments, rays, and lines. Further, a more general notion of non-annular bounded…

Geometric Topology · Mathematics 2010-05-28 Jeffrey Brock , Howard Masur , Yair Minsky

We study encodings that give the best known thresholds for the non-zero capacity of quantum channels, i.e., the upper bound for correctable noise, using an entropic approach to calculation of the threshold values. Our results show that…

Quantum Physics · Physics 2009-02-22 Jesse Fern , K. Birgitta Whaley

Let $L$ be a Galois algebra with Galois group $G$ and let $x$ be a normal element of $L$. The moduli space $\mathcal X$ of pairs $(L,x)$ is isomorphic to an open subset of the quotient variety $\mathbb P/G$, where $\mathbb P$ is the…

Number Theory · Mathematics 2023-03-14 Andrew O'Desky , Julian Rosen

We prove a randomized version of the generalized Urysohn inequality relating mean-width to the other intrinsic volumes. To do this, we introduce a stochastic approximation procedure that sees each convex body K as the limit of intersections…

Metric Geometry · Mathematics 2016-06-30 Grigoris Paouris , Peter Pivovarov