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We consider isometric immersions of complete connected Riemannian manifolds into space forms of nonzero constant curvature. We prove that if such an immersion is compact and has semi-definite second fundamental form, then it is an embedding…

Differential Geometry · Mathematics 2018-03-22 Ronaldo F. de Lima , Rubens L. de Andrade

For an interval finite quiver $Q$, we introduce a class of flat representations. We classify the indecomposable projective objects in the category $\mathrm{rep}(Q)$ of pointwise finite dimensional representations. We show that an object in…

Representation Theory · Mathematics 2019-10-23 Pengjie Jiao

We study the repetition of patches in self-affine tilings in R^d. In particular, we study the existence and non-existence of arithmetic progressions. We first show that an arithmetic condition of the expansion map for a self-affine tiling…

Dynamical Systems · Mathematics 2021-07-01 Yasushi Nagai , Shigeki Akiyama , Jeong-Yup Lee

We consider transcendental entire functions of finite order for which the zeros and $1$-points are in disjoint sectors. Under suitable hypotheses on the sizes of these sectors we show that such functions must have a specific form, or that…

Complex Variables · Mathematics 2020-12-29 Walter Bergweiler , Alexandre Eremenko

We show that for every $1<n<\infty$, there exits a Banach space $X_n$ containing proximinal subspaces of codimension $n$ but no proximinal finite codimensional subspaces of higher codimension. Moreover, the set of norm-attaining functionals…

Functional Analysis · Mathematics 2019-12-18 Miguel Martin

We construct supersymmetric quantum mechanics in terms of two real supercharges on noncommutative space in arbitrary dimensions. We obtain the exact eigenspectra of the two and three dimensional noncommutative superoscillators. We further…

High Energy Physics - Theory · Physics 2009-01-07 Pijush K. Ghosh

We show that semiprojectivity of a C*-algebra is preserved when passing to C*-subalgebras of finite codimension. In particular, any pullback of two semiprojective C*-algebras over a finite-dimensional C*-algebra is again semiprojective.

Operator Algebras · Mathematics 2014-05-13 Dominic Enders

We establish a structure theorem for degree three codimension one foliations on projective spaces of dimension $n\ge 3$, extending a result by Loray, Pereira, and Touzet for degree three foliations on $\mathbb P^3$. We show that the space…

Algebraic Geometry · Mathematics 2021-12-13 Raphael Constant da Costa , Ruben Lizarbe , Jorge Vitório Pereira

We show that the hyperkahler geometry of $T^*\mathbb{CP}^{n-1}$ can be described algebraically by the affine scheme of rank-1 projections, and that this description simultaneously yields explicit $SU(n)$-equivariant isometric embeddings \[…

Algebraic Geometry · Mathematics 2026-03-27 Joshua Lackman

We prove the projective plane $\rp^2$ is an absolute extensor of a finite-dimensional metric space $X$ if and only if the cohomological dimension mod 2 of $X$ does not exceed 1. This solves one of the remaining difficult problems (posed by…

Geometric Topology · Mathematics 2014-10-01 Jerzy Dydak , Michael Levin

We prove the boundedness of Bergman type projections in two different analytic function spaces in bounded strongly pseudoconvex domains with the smooth boundary. Our results were previously well-known in the case of the unit disk.

Complex Variables · Mathematics 2025-08-28 R. F. Shamoyan , E. B. Tomashevskaya

As in the case of the associahedron and cyclohedron, the permutohedron can also be defined as an appropriate compactification of a configuration space of points on an interval or on a circle. The construction of the compactification endows…

Algebraic Topology · Mathematics 2009-04-23 P. Lambrechts , V. Tourtchine , I. Volic

We study the structure of bounded linear functionals on a class of non-self-adjoint operator algebras that includes the multiplier algebra of every complete Nevanlinna-Pick space, and in particular the multiplier algebra of the…

Operator Algebras · Mathematics 2016-01-20 Matthew Kennedy , Dilian Yang

We give a new proof that bounded non-commutative functions on polynomial polyhedra can be represented by a realization formula, a generalization of the transfer function realization formula for bounded analytic functions on the unit disk.

Functional Analysis · Mathematics 2019-08-15 Jim Agler , John E. McCarthy

We show that the algebra of functions on noncommutative space allows two different representations. One is describing the genuine noncommutative space, while another one can be rewritten in commutative form by a redefinition of generators.

High Energy Physics - Theory · Physics 2009-02-05 Corneliu Sochichiu

In this article we classify totally geodesic submanifolds in arbitrary products of rank one symmetric spaces. Furthermore, we give infinitely many examples of irreducible totally geodesic submanifolds in Hermitian symmetric spaces with…

Differential Geometry · Mathematics 2024-06-06 A. Rodríguez-Vázquez

Let X be an L_1-predual space and let K be a countable linearly independent subset of the extreme points of its closed dual ball. It is shown that if the norm-closed linear span Y of K is w^*-closed in X^*, then Y is the range of a…

Functional Analysis · Mathematics 2007-05-23 Ioannis Gasparis

Gelfand - Na\u{i}mark theorem supplies a one to one correspondence between commutative $C^*$-algebras and locally compact Hausdorff spaces. So any noncommutative $C^*$-algebra can be regarded as a generalization of a topological space.…

Operator Algebras · Mathematics 2014-10-28 Petr Ivankov

We obtain a structure theorem for closed, cohomogeneity one Alexandrov spaces and we classify closed, cohomogeneity one Alexandrov spaces in dimensions 3 and 4. As a corollary, we obtain the classification of closed, $n$-dimensional,…

Differential Geometry · Mathematics 2010-09-21 Fernando Galaz-Garcia , Catherine Searle

Wigner's theorem characterizes isometries of the set of all rank one projections on a Hilbert space. In metric geometry nonexpansive maps and noncontractive maps are well studied generalizations of isometries. We show that under certain…

Mathematical Physics · Physics 2025-08-20 Michiya Mori , Peter Šemrl