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We study relations of some classes of $k$-convex, $k$-visible bodies in Euclidean spaces. We introduce and study \textrm{circular projections} in normed linear spaces and classes of bodies related with families of such maps, in particular,…

Metric Geometry · Mathematics 2015-12-31 V. Golubyatnikov V. Rovenski

When studying mirror symmetry in the context of K3 surfaces, the hyperkaehler structure of K3 makes the notion of exchanging Kaehler and complex moduli ambiguous. On the other hand, the metric is not renormalized due to the higher amount of…

High Energy Physics - Theory · Physics 2007-05-23 Falk Rohsiepe

The purpose of this note is to present several aspects of concentration phenomena in high dimensional geometry. At the heart of the study is a geometric analysis point of view coming from the theory of high dimensional convex bodies. The…

Functional Analysis · Mathematics 2013-10-07 Olivier Guédon

We study geometric consistency relations between angles on 3-dimensional (3D) circular quadrilateral lattices -- lattices whose faces are planar quadrilaterals inscribable into a circle. We show that these relations generate canonical…

High Energy Physics - Theory · Physics 2008-11-26 Vladimir V. Bazhanov , Vladimir V. Mangazeev , Sergey M. Sergeev

The optical medium analogy of a radiation field generated by either an exact gravitational plane wave or an exact electromagnetic wave in the framework of general relativity is developed. The equivalent medium of the associated background…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Donato Bini , Pierluigi Fortini , Andrea Geralico , Maria Haney , Antonello Ortolan

Partially coherent electromagnetic sources with cylindrical symmetry and infinite extent radiating outwards are introduced. Their $3\times3$ cross-spectral density matrix is given through expansions of the field components in terms of basis…

The mechanics of an oriented point (point with "spin") based on 3D and 4D Frenet equations is considered. In such mechanics there is an opportunity to describe formally any physical trajectory of a particle with own rotation. We use…

General Relativity and Quantum Cosmology · Physics 2017-02-09 Trukhanova Mariya , Shipov Gennady

This paper is a continuation and an extension of our recent work [3] on the geometric structures of Laplacian eigenfunctions and their applications to inverse scattering problems. In [3], the analytic behaviour of the Laplacian…

Analysis of PDEs · Mathematics 2019-09-24 Xinlin Cao , Huaian Diao , Hongyu Liu , Jun Zou

We prove that if two convex bodies $ K, L \subset \mathbb{R}^3$ satisfy the property that the orthogonal projections of $K$ and $L$ onto every plane containing the origin are roations of each other, then either $K$ and $L$ coincide or $L$…

Classical Analysis and ODEs · Mathematics 2013-09-30 Benjamin Mackey

The three-dimensional linear regression problem is a problem of finding a spacial straight line best fitting a group of points in three-dimensional Euclidean space. This problem is considered in the present paper and a solution to it is…

Computational Geometry · Computer Science 2019-07-16 O. V. Ageev , R. A. Sharipov

To understand how the human visual system analyzes images, it is essential to know the structure of the visual environment. In particular, natural images display consistent statistical properties that distinguish them from random luminance…

Disordered Systems and Neural Networks · Physics 2014-03-05 M. Sigman , G. A. Cecchi , C. D. Gilbert , M. O. Magnasco

We study the geometric quantization on $K3$ surfaces from the viewpoint of the spectral convergence. We take a special Lagrangian fibrations on the $K3$ surfaces and a family of hyper-K\"ahler structures tending to large complex structure…

Differential Geometry · Mathematics 2023-04-07 Kota Hattori

We study moduli spaces of lattice-polarized K3 surfaces in terms of orbits of representations of algebraic groups. In particular, over an algebraically closed field of characteristic 0, we show that in many cases, the nondegenerate orbits…

Algebraic Geometry · Mathematics 2017-07-03 Manjul Bhargava , Wei Ho , Abhinav Kumar

Euclidean distance geometry is the study of Euclidean geometry based on the concept of distance. This is useful in several applications where the input data consists of an incomplete set of distances, and the output is a set of points in…

Quantitative Methods · Quantitative Biology 2012-05-03 Leo Liberti , Carlile Lavor , Nelson Maculan , Antonio Mucherino

We define two transforms between non-conformal harmonic maps from a surface into the 3-sphere. With these transforms one can construct, from one such harmonic map, a sequence of harmonic maps. We show that there is a correspondence between…

Differential Geometry · Mathematics 2014-11-19 Bart Dioos , Joeri Van der Veken , Luc Vrancken

This paper will extend a known relationship between the circumradius and dihedral angles of a tetrahedron in three-dimensional Euclidean space to three-dimensional affine space over a general field not of characteristic two, using only the…

Metric Geometry · Mathematics 2021-01-28 Gennady Arshad Notowidigdo

Partially coherent electromagnetic sources with cylindrical symmetry and infinite extent radiating outwards are introduced. Their 3x3 cross-spectral density matrix is given through expansions of the field components in terms of basis…

A well-known object in classical Euclidean geometry is the circumcenter of a triangle, i.e., the point that is equidistant from all vertices. The purpose of this paper is to provide a systematic study of the circumcenter of sets containing…

Optimization and Control · Mathematics 2018-07-06 Heinz H. Bauschke , Hui Ouyang , Xianfu Wang

A holographic correspondence between data on horizon and space-time physics is investigated. We find similarities with the AdS/CFT correspondence, based on the observation that the optical metric near the horizon describes a Euclidean…

High Energy Physics - Theory · Physics 2014-11-18 Ivo Sachs , Sergey N. Solodukhin

We investigate the vertex curve, that is the set of points in the hyperbolic region of a smooth surface in real 3-space at which there is a circle in the tangent plane having at least 5-point contact with the surface. The vertex curve is…

Differential Geometry · Mathematics 2021-08-31 Peter Giblin , Graham Reeve , Ricardo Uribe-Vargas