Results 21 to 30 of about 157,767 (127)

Simultaneous approximation of a real number by all conjugates of an algebraic number

open access: yes, 2007
Using a method of H. Davenport and W. M. Schmidt, we show that, for each positive integer n, the ratio 2/n is the optimal exponent of simultaneous approximation to real irrational numbers 1) by all conjugates of algebraic numbers of degree n, and 2) by ...
Alain, Guillaume
core   +1 more source

Simultaneous rational approximations to algebraic numbers [PDF]

open access: yesBulletin of the American Mathematical Society, 1961
Let \(\beta_1, \beta_2, \dots,\beta_n\) be linearly independent numbers of a real algebraic number field of degree \(n+1\). By a study of the units of the field it is shown how to obtain all integral solutions of the set of inequalities: \[ q_0>0, \quad\gcd(q_0,q_1,\dots,q_n)=1,\quad | \beta_j/\beta_0-q_j/q_0| < Cq_0^{-1-1/n} \] for fixed \(C\).
openaire   +3 more sources

A Hyper-Dual Number Approach to Higher-Order Derivative Computation

open access: yesAxioms
This paper develops a theoretical framework for the computation of higher-order derivatives based on the algebra of hyper-dual numbers. Extending the classical dual number system, hyper-dual numbers provide a natural and rigorous mechanism for encoding ...
Ji Eun Kim
doaj   +1 more source

The Polyhedron-Hitting Problem [PDF]

open access: yes, 2014
We consider polyhedral versions of Kannan and Lipton's Orbit Problem (STOC '80 and JACM '86)---determining whether a target polyhedron V may be reached from a starting point x under repeated applications of a linear transformation A in an ambient vector ...
Chonev, Ventsislav   +2 more
core   +2 more sources

Normal Shock Wave Approximations for Flight at Hypersonic Mach Numbers

open access: yesAerospace
Normal shock pressure ratios in equilibrium air for Mach numbers up to 30 and altitudes to 300,000 feet are shown to be correlated by a simple power law which provides an accuracy of ±2%, thereby permitting direct calculation of corresponding enthalpy ...
Pasquale M. Sforza
doaj   +1 more source

Chromatic homotopy theory is asymptotically algebraic

open access: yes, 2019
Inspired by the Ax--Kochen isomorphism theorem, we develop a notion of categorical ultraproducts to capture the generic behavior of an infinite collection of mathematical objects.
Barthel, Tobias   +2 more
core   +2 more sources

Tropical Solution of Discrete Best Approximation Problems

open access: yesMathematics
We consider discrete best approximation problems in the setting of tropical algebra, which is concerned with the theory and application of algebraic systems with idempotent operations. Given a set of input–output pairs of an unknown function defined on a
Nikolai Krivulin
doaj   +1 more source

Exact Real Arithmetic with Perturbation Analysis and Proof of Correctness [PDF]

open access: yes, 2015
In this article, we consider a simple representation for real numbers and propose top-down procedures to approximate various algebraic and transcendental operations with arbitrary precision.
Groote, Jan Friso, Keshishzadeh, Sarmen
core   +2 more sources

Report on some recent advances in Diophantine approximation [PDF]

open access: yes, 2009
A basic question of Diophantine approximation, which is the first issue we discuss, is to investigate the rational approximations to a single real number. Next, we consider the algebraic or polynomial approximations to a single complex number, as well as
Waldschmidt, Michel
core   +3 more sources

Explicit Lower Bounds for Rational Approximation to Algebraic Numbers [PDF]

open access: yesProceedings of the London Mathematical Society, 1997
The author gives irrationality measures for some algebraic numbers of degree at least 4. A typical example is \(|{\root 4 \of{5}} -p/q |> 0.03 q^{-2.77}\) for \(p\), \(q\in \mathbb{N}\). This is obtained by using Padé approximation of the binomial function \((1+ x)^\alpha\), with a careful study of the divisibility properties of the coefficients of the
openaire   +3 more sources

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