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Related papers: On Birkhoff angles in normed spaces

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We introduce a new $2$-norm on a normed space using a semi-inner product $g$ on the space. Using the $2$-norm, we propose a formula for the $g$-angle between $2$-dimensional subspaces in the space. Our formula serves as a revision of the…

Functional Analysis · Mathematics 2019-02-26 Muhammad Nur , Hendra Gunawan

The Birkhoff's theorem states that any doubly stochastic matrix lies inside a convex polytope with the permutation matrices at the corners. It can be proven that a similar theorem holds for unitary matrices with equal line sums for prime…

Mathematical Physics · Physics 2016-06-16 Alexis De Vos , Stijn De Baerdemacker

In this article, we generalize the notion of orthogonality as a linear combination of norm derivatives in order to give a novel concept that we refer to as $\rho_{\alpha,\beta}$-orthogonality. Also, we discuss some of its geometric…

Functional Analysis · Mathematics 2023-10-12 Kallal Pal , Sumit Chandok

We investigate metric projections and distance functions referring to convex bodies in finite-dimensional normed spaces. For this purpose we identify the vector space with its dual space by using, instead of the usual identification via the…

Metric Geometry · Mathematics 2019-08-26 Vitor Balestro , Horst Martini , Ralph Teixeira

We consider the angle in mathematics and arrive at a conclusion that there are two concepts on the issue. One is a descriptive geometrical one, while the other is from functional analysis. They are somewhat different, allow for different…

History and Philosophy of Physics · Physics 2024-04-15 Savely G. Karshenboim

We first define a complex angle between two oriented spacelike planes in 4-dimensional Minkowski space, and then study the constant angle surfaces in that space, i.e. the oriented spacelike surfaces whose tangent planes form a constant…

Differential Geometry · Mathematics 2019-07-24 Pierre Bayard , Juan Monterde , Raúl C. Volpe

Author developed a uniform model for different spaces where distance and angle measure kinds are parameters. This model is calculus centric, but can also be used in theoretical research. It is useful in the following domains: deduction of…

Metric Geometry · Mathematics 2018-07-30 Alexandru Popa

In this paper, we study main properties of cone normed spaces, and prove some theorems of weighted means in cone normed spaces.

Functional Analysis · Mathematics 2010-06-29 Ayse Sonmez , Huseyin Cakalli

We derive analytical expressions for the solid angle subtended by a right circular cylinder at a point source with cosine angular distribution in the case where the source and the cylinder axes are mutually orthogonal.

Mathematical Physics · Physics 2009-11-07 M. J. Prata

We introduce an alternative formalization of curved spaces in which the concept of a pointwise affine space, as defined here, replaces that of a manifold. New or modified definitions of familiar notions from differential geometry such as…

Differential Geometry · Mathematics 2025-09-09 Dan Jonsson

Angular equivalence is introduced and shown to be an equivalence relation among the norms on a fixed real vector space. It is a finer notion than the usual (topological) notion of norm equivalence. Angularly equivalent norms share certain…

Functional Analysis · Mathematics 2023-01-18 Eder Kikianty , Gord Sinnamon

We extend the notion of randomness (in the version introduced by Schnorr) to computable Probability Spaces and compare it to a dynamical notion of randomness: typicality. Roughly, a point is typical for some dynamic, if it follows the…

Probability · Mathematics 2009-02-12 Peter Gacs , Mathieu Hoyrup , Cristobal Rojas

In this paper, we introduce the notion of bicomplex partial b-metric space and prove some common fixed point theorems. Our results generalize and expand some of the literature's well known results. We also explore some of the applications…

Functional Analysis · Mathematics 2021-07-12 Gunaseelan Mani , Arul Joseph Gnanaprakasam , Yongjin Li , Zhaohui Gu

We introduce the notion of orthogonality in a vector space with a topology on it. To serve our purpose, we define orthogonality space for a given vector space X, using the topology on it. We show that for a suitable choice of orthogonality…

Functional Analysis · Mathematics 2019-10-28 Debmalya Sain , Saikat Roy , Kallol Paul

The Grassmann angle improves upon similar angles between subspaces that measure volume contraction in orthogonal projections. It works in real or complex spaces, with important differences, and is asymmetric, what makes it more efficient…

Metric Geometry · Mathematics 2021-01-13 André L. G. Mandolesi

Principal angles are used to define an angle bivector of subspaces, which fully describes their relative inclination. Its exponential is related to the Clifford geometric product of blades, gives rotors connecting subspaces via minimal…

Metric Geometry · Mathematics 2021-09-23 André L. G. Mandolesi

We study the concepts of Birkhoff--James orthogonality and parallelism in Hilbert space operators, induced by the operator radius norm $w_{\rho}(\cdot)$. In particular, we completely characterize Birkhoff--James orthogonality and…

Functional Analysis · Mathematics 2024-05-14 Fuad Kittaneh , Ali Zamani

We consider an undamped nonlinear hinged-hinged beam with stretching nonlinearity as an infinite dimensional hamiltonian system. We obtain analytically a quantitative Birkhoff Normal Form, via a nonlinear coordinate transformation that…

Analysis of PDEs · Mathematics 2024-10-01 Laura Di Gregorio , Walter Lacarbonara

To determine the relative position of any two surfaces in a system, one approach is to useoperations (Minkowski sum and intersection) on sets of constraints. These constraints aremade compliant with half-spaces of R^n where each set of…

Computational Geometry · Computer Science 2015-09-30 Lazhar Homri , Denis Teissandier , Alex Ballu

We first review the definition of the angle between subspaces and how it is computed using matrix algebra. Then we introduce the Grassmann and Clifford algebra description of subspaces. The geometric product of two subspaces yields the full…

Metric Geometry · Mathematics 2013-06-11 Eckhard Hitzer