Results 51 to 60 of about 63,567 (182)

On characterizing potential friends of 20

Annals of the West University of Timisoara: Mathematics and Computer Science
Does 20 have a friend? Or is it a solitary number? A folklore conjecture asserts that 20 has no friends, i.e., it is a solitary number. In this article, we prove that a friend N of 20 is of the form N = 2 · 52a ·m2, with (3;m) = (7;m) = 1 and it has at ...
Chatterjee Tapas, Mandal Sagar, Mandal Sourav   +2 more
doaj   +1 more source

Automorphism groups of Grassmann codes

, 2013
We use a theorem of Chow (1949) on line-preserving bijections of Grassmannians to determine the automorphism group of Grassmann codes. Further, we analyze the automorphisms of the big cell of a Grassmannian and then use it to settle an open question of ...
Artin, Beelen, Beelen, Berger, Bogart, Chow, Ghorpade, Ghorpade, Griffiths, Harris, Hirschfeld, Hodge, Krishna V. Kaipa, Lakshmibai, MacWilliams, Nemitz, Nogin, Pankov, Prażmowski, Sudhir R. Ghorpade, Tsfasman, Tsfasman, Wan, Ward, Westwick   +24 more
core   +2 more sources

Time‐resolved XPCS analysis across broad time‐scales using multi‐tau two‐time correlations

Journal of Synchrotron Radiation, EarlyView.
A scalable multi‐tau two‐time correlation framework enables efficient, time‐resolved XPCS analysis of long duration high‐frame‐rate modern synchrotron data while preserving sensitivity to non‐stationary dynamics.We present a multi‐tau two‐time correlation (MT‐2TC) analysis for X‐ray photon correlation spectroscopy that enables efficient analysis of ...
Fabio Brugnara, Marco Cammarata, Yuriy Chushkin, Irene Festi, Massimo Granata, David Hofman, Matteo Leonardi, Daniele Marzi, Denis Nabari, Angela Trapananti, Simone Ziglio, Federico Zontone, Marco Zanatta, Giacomo Baldi   +13 more
wiley   +1 more source

Computing in Jacobians of projective curves over finite fields

, 2010
We give algorithms for computing with divisors on projective curves over finite fields, and with their Jacobians, using the algorithmic representation of projective curves developed by Khuri-Makdisi.
Bruin, Peter
core   +1 more source

A fast metaheuristic approach for the planar multiple obnoxious facility location problem

International Transactions in Operational Research, EarlyView.
Abstract The multiple obnoxious facility location problem is one of the most studied problems in the literature of the obnoxious facility location problems family. In this work, we propose an alternative algorithmic approach for this problem, based on an efficient metaheuristic procedure over a discretization of the plane based on Voronoi diagrams ...
Sergio Salazar, Abraham Duarte, J. Manuel Colmenar   +2 more
wiley   +1 more source

Prime divisors of some shifted products

International Journal of Mathematics and Mathematical Sciences, 2005
We study prime divisors of various sequences of positive integers A(n)+1, n=1,…,N, such that the ratios a(n)=A(n)/A(n−1) have some number-theoretic or combinatorial meaning.
Eric Levieil, Florian Luca, Igor E. Shparlinski   +2 more
doaj   +1 more source

Testing for Unspecified Periodicities in Binary Time Series

Journal of Time Series Analysis, EarlyView.
ABSTRACT Given random variables Y1,…,Yn$$ {Y}_1,\dots, {Y}_n $$ with Yi∈{0,1}$$ {Y}_i\in \left\{0,1\right\} $$ we test the hypothesis whether the underlying success probabilities pi$$ {p}_i $$ are constant or whether they are periodic with an unspecified period length of r≥2$$ r\ge 2 $$.
Finn Schmidtke, Mathias Vetter
wiley   +1 more source

A characterization of the algebra of holomorphic functions on a simply connected domain

International Journal of Mathematics and Mathematical Sciences, 1989
Let A be a singly-generated ℱ-algebra. It is shown that A isomorphic to H(Ω) where Ω is a simply connected domain in ℂ if and only if A has no topological divisors of zero.
Derming Wang, Saleem Watson
doaj   +1 more source

On the explicit geometry of a certain blowing-up of a smooth quadric

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2023
Using the high symmetry in the geometry of a smooth projective quadric, we construct effectively new families of smooth projective rational surfaces whose nef divisors are regular, and whose effective monoids are finitely generated by smooth projective ...
De La Rosa-Navarro B. L., Failla G., Frías-Medina J. B., Lahyane M., Utano R.   +4 more
doaj   +1 more source

Structure and Computation

Noûs, EarlyView.
ABSTRACT It is a truism of mathematics that differences between isomorphic number systems are irrelevant to arithmetic. This truism is deeply rooted in the modern axiomatic method and underlies most strands of arithmetical structuralism, the view that arithmetic is about some abstract number structure.
Balthasar Grabmayr
wiley   +1 more source