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In this paper, we begin by showing a new generalization of the celebrated Cauchy-Schwarz inequality for the inner product. Then, this generalization is used to present some bounds for the Euclidean operator radius and the Euclidean operator…

Functional Analysis · Mathematics 2023-10-09 Mohammad Sababheh , Hamid Reza Moradi

Szemer\'edi's regularity lemma is a fundamental tool in extremal graph theory, theoretical computer science and combinatorial number theory. Lov\'asz and Szegedy [L. Lov\'asz and B. Szegedy: Szemer\'edi's Lemma for the analyst, Geometric…

Combinatorics · Mathematics 2015-06-24 Guus Regts

In this paper we extend our findings in [3] and answer further questions regarding continuity and discontinuity of seminorms on infinite-dimensional vector spaces.

Functional Analysis · Mathematics 2020-03-10 Jacek Chmieliński , Moshe Goldberg

We resolve a long-standing open problem posed by Federer concerning the rectifiability of the integral geometric measure with exponent p >1, thereby settling a question that has persisted since its formulation. While the main theorem is…

Metric Geometry · Mathematics 2025-08-12 Emanuele Tasso

It is well known that the description of topological and geometric properties of bisectors in normed spaces is a non-trivial subject. In this paper we introduce the concept of bounded representation of bisectors in finite dimensional real…

Geometric Topology · Mathematics 2010-02-02 Á. G. Horváth , H. Martini

We show that the classes of separable reflexive Banach spaces and of spaces with separable dual are strongly bounded. This gives a new proof of a recent result of E. Odell and Th. Schlumprecht, asserting that there exists a separable…

Functional Analysis · Mathematics 2007-05-23 Pandelis Dodos , Valentin Ferenczi

We obtain boundedness for the bilinear spherical maximal function in a range of exponents that includes the Banach triangle and a range of $L^p$ with $p<1$. We also obtain counterexamples that are asymptotically optimal with our positive…

Classical Analysis and ODEs · Mathematics 2017-04-13 J. A. Barrionevo , Loukas Grafakos , Danqing He , Petr Honzík , Lucas Oliveira

In this paper we approach the problem of perturbation from symmetry of strongly indefinite elliptic systems in dimension N>=3. We prove the existence of infinitely many solutions under suitable growth coinditions on the nonlinear terms.

Analysis of PDEs · Mathematics 2007-05-23 Cristina Tarsi

In this paper, we describe the structure of shape derivatives around sets which are only assumed to be of finite perimeter in $\R^N$. This structure allows us to define a useful notion of positivity of the shape derivative and we show it…

Optimization and Control · Mathematics 2007-05-23 Jimmy Lamboley , Michel Pierre

We establish a uniform Sobolev inequality for K\"ahler metrics, which only require an entropy bound and no lower bound on the Ricci curvature. We further extend our Sobolev inequality to singular K\"ahler metrics on K\"ahler spaces with…

Differential Geometry · Mathematics 2023-11-02 Bin Guo , Duong H. Phong , Jian Song , Jacob Sturm

We establish existence results for a class of mixed anisotropic and nonlocal $p$-Laplace equation with singular nonlinearities. We consider both constant and variable singular exponents. Our argument is based on an approximation method. To…

Analysis of PDEs · Mathematics 2023-03-28 Prashanta Garain , Wontae Kim , Juha Kinnunen

We extend an example of B. Aupetit, which illustrates spectral discontinuity for operators on an infinite dimensional separable Hilbert space, to a general spectral discontinuity result in abstract Banach algebras. This can then be used to…

Functional Analysis · Mathematics 2018-08-10 Rudi Brits

We generalize to any q a theorem about covering radius of linear codes proved by Helleseth, Klove and Mykkelvit. Then we determine the covering radius of first order generalized Reed-Muller codes in second order generalized Reed-Muller…

Number Theory · Mathematics 2011-02-11 Elodie Leducq

Recall that the radius of a compact metric space $(X, dist)$ is given by $rad\ X = \min_{x\in X} \max_{y\in X} dist(x,y)$. In this paper we generalize Berger's $\frac{1}{4}$-pinched rigidity theorem and show that a closed, simply connected,…

dg-ga · Mathematics 2008-02-03 Frederick Wilhelm

We present sharp lower bounds for the A-numerical radius of semi-Hilbertian space operators. We also present an upper bound. Further we compute new upper bounds for the $B$-numerical radius of $2 \times 2$ operator matrices where $B =…

Functional Analysis · Mathematics 2020-04-22 Pintu Bhunia , Raj Kumar Nayak , Kallol Paul

A problem of Banach asks whether every infinite-dimensional Banach space which is isomorphic to all its infinite-dimensional subspaces must be isomorphic to a separable Hilbert space. In this paper we prove a result of a Ramsey-theoretic…

Functional Analysis · Mathematics 2007-05-23 W. T. Gowers

We consider the Cauchy problem for (energy-subcritical) nonlinear Schr\"odinger equations with sub-quadratic external potentials and an additional angular momentum rotation term. This equation is a well-known model for superfluid quantum…

Analysis of PDEs · Mathematics 2013-02-08 Paolo Antonelli , Daniel Marahrens , Christof Sparber

We extend the recursion formula for matrix Bessel functions, which we obtained previously, to superspace. It is sufficient to do this for the unitary orthosymplectic supergroup. By direct computations, we show that fairly explicit results…

Mathematical Physics · Physics 2007-05-23 Th. Guhr , H. Kohler

Sectional curvature bounds are of central importance in the study of Riemannian manifolds, both in smooth differential geometry and in the generalized synthetic setting of Alexandrov spaces. Riemannian metrics along with metric spaces of…

Differential Geometry · Mathematics 2026-01-30 Darius Erös , Michael Kunzinger , Argam Ohanyan , Alessio Vardabasso

In this article, we proved upper bounds for numerical radius of bounded linear operator and product of operators which generalize and improve existing inequalities. We also obtain a numerical radius inequality of invertible operator using…

Functional Analysis · Mathematics 2023-04-03 Raj Kumar Nayak