English
Related papers

Related papers: Sp\'eculation sur la g\'eom\'etrie en \'Egypte ant…

200 papers

Large-scale structure (LSS) studies in cosmology map and analyse matter in the Universe on the largest scales. Understanding the LSS can provide observational support for the Cosmological Principle (CP) and the Standard Cosmological Model…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-24 Alexia M. Lopez , Roger G. Clowes , Gerard M. Williger

One of the goals that physicists have been pursuing is to get the same explanation from different angles for the same phenomenon, so as to realize the unity of basic physical laws. Geometry, classical mechanics and classical thermodynamics…

Classical Physics · Physics 2021-02-02 Weicong Xu , Li Zhao

The three dimensional structure of large packings of monosized spheres with volume fractions ranging between 0.58 and 0.64 has been studied with X-ray Computed Tomography. We search for signatures of organization, we classify local…

Soft Condensed Matter · Physics 2007-09-19 T. Aste , M. Saadatfar , T. J. Senden

A re-calculation of a known family of formulas of PI is carried out, revisiting the old Archimedes' algorithm. This allows to identify a general family equation and three new simple formulas of Pi in terms of the golden ratio PHI in the…

General Mathematics · Mathematics 2024-04-12 Angelo Pignatelli

This article explores the overall geometric manner in which human beings make sense of the world around them by means of their physical theories; in particular, in what are nowadays called pregeometric pictures of Nature. In these, the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Diego Meschini , Markku Lehto , Johanna Piilonen

Measures of erythrocytes volume and surface are helpful in several physiological studies, both for zoologists and veterinarians. Whilst diameter and volume are assessed with ease from observations of blood smears and complete blood count,…

Quantitative Methods · Quantitative Biology 2024-06-10 Ion Udroiu

In classical physics, a single measurement can in principle reveal the state of a system. However, quantum theory permits numerous non-equivalent measurements on a physical system, each providing only limited information about the state.…

Quantum Physics · Physics 2024-03-01 Yang Yu , Philip Goyal

One of the oldest and most enduring myths in human history is the belief that the Parthenon was cleverly designed with various curved structures and sizes in order to correct optical illusions, and therefore appear straight and regular. The…

History and Overview · Mathematics 2026-04-07 Alain Goriely

The direct gravimetry problem is solved using the subdivision of each body of a deposit into a set of vertical adjoining bars, and in the inverse problem each body of a deposit is modeled by a uniform ellipsoid of revolution (spheroid).…

Numerical Analysis · Mathematics 2015-08-19 Valery Sizikov

I present here a measurement of pi as determined for the largest observable circles. Intriguingly, the value of 16/5 asserted by the House of Representatives of the State of Indiana in 1897 is still viable, although strongly disfavored…

Popular Physics · Physics 2012-04-03 Lloyd Knox

Many algorithmic problems can be solved (almost) as efficiently in metric spaces of bounded doubling dimension as in Euclidean space. Unfortunately, the metric space defined by points in a simple polygon equipped with the geodesic distance…

Computational Geometry · Computer Science 2026-04-20 Mark de Berg , Prosenjit Bose , Leonidas Theocharous

The mathematical problems and their solutions of the Third International Students' Olympiad in Cryptography NSUCRYPTO'2016 are presented. We consider mathematical problems related to the construction of algebraic immune vectorial Boolean…

Cryptography and Security · Computer Science 2017-10-17 N. Tokareva , A. Gorodilova , S. Agievich , V. Idrisova , N. Kolomeec , A. Kutsenko , A. Oblaukhov , G. Shushuev

It is attempted to obtain the masses of the celestial bodies, the initial conditions of their motion, and the constant of gravitation, by a global parameter optimization. First, a numerical solution of the N-bodies problem for mass points…

Astrophysics · Physics 2007-05-23 Mayeul Arminjon

The horologia are ancient ephemerides, tables of durations of the days and nights during all months of the year. The algorithms used to compute the horologia are here presented and the results are compared with the tables computed by…

History and Philosophy of Physics · Physics 2012-11-13 Costantino Sigismondi

The space of shapes of a polyhedron with given total angles less than 2\pi at each of its n vertices has a Kaehler metric, locally isometric to complex hyperbolic space CH^{n-3}. The metric is not complete: collisions between vertices take…

Geometric Topology · Mathematics 2007-05-23 William P. Thurston

The large-scale structure of the Universe is well approximated by the Friedmann equations, parametrized by several energy densities which can be observationally inferred. A natural question to ask is: How different would the Universe be if…

General Relativity and Quantum Cosmology · Physics 2025-01-20 Arthur G. Suvorov

We investigate the complexity of counting the number of integer points in tropical polytopes, and the complexity of calculating their volume. We study the tropical analogue of the outer parallel body and establish bounds for its volume. We…

Computational Complexity · Computer Science 2019-12-30 Stephane Gaubert , Marie MacCaig

In [1], the author considered the problem of the optimal approximation of symmetric surfaces by biquadratic B\'ezier patches. Unfortunately, the results therein are incorrect, which is shown in this paper by considering the optimal…

Numerical Analysis · Mathematics 2023-03-09 Aleš Vavpetič , Emil Žagar

It is shown here how prior estimates on the local shape of the universe can be used to reduce, to a small region, the full parameter space for the search of circles in the sky. This is the first step towards the development of efficient…

Astrophysics · Physics 2007-05-23 G. I. Gomero

The honeycomb problem on the sphere asks for the perimeter-minimizing partition of the sphere into N equal areas. This article solves the problem when N=12. The unique minimizer is a tiling of 12 regular pentagons in the dodecahedral…

Metric Geometry · Mathematics 2007-05-23 Thomas C. Hales