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Related papers: A note on exact approximations

200 papers

We study how well a real number can be approximated by sums of two or more rational numbers with denominators up to a certain size.

Number Theory · Mathematics 2007-05-23 Tsz Ho Chan , Angel V. Kumchev

Probably we have observed a new simple phenomena dealing with approximations to two real numbers.

Number Theory · Mathematics 2009-10-14 Igor D. Kan , Nikolay G. Moshchevitin

In this note we formulate some questions in the study of approximations of reals by rationals of the form a/b^2 arising in theory of Shr"odinger equations. We hope to attract attention of specialists to this natural subject of number…

Number Theory · Mathematics 2007-05-23 Oleg Karpenkov

A simple proof is given of the known fact that an m-times continuously differentiable function on the real line can be approximated along with its derivatives by an entire function and its respective derivatives.

Complex Variables · Mathematics 2019-08-15 Paul M. Gauthier , Julie Kienzle

We consider the question of approximating any real number $\alpha$ by sums of $n$ rational numbers $\frac{a_1}{q_1} + \frac{a_2}{q_2} + ... + \frac{a_n}{q_n}$ with denominators $1 \leq q_1, q_2, ..., q_n \leq N$. This leads to an inquiry on…

Number Theory · Mathematics 2007-05-23 Tsz Ho Chan

We give a new proof of a classical theorem on approximation of continuous functions on totally real sets

Complex Variables · Mathematics 2008-05-23 Bo Berndtsson

We generalize Dirichlet's diophantine approximation theorem to approximating any real number $\alpha$ by a sum of two rational numbers $\frac{a_1}{q_1} + \frac{a_2}{q_2}$ with denominators $1 \leq q_1, q_2 \leq N$. This turns out to be…

Number Theory · Mathematics 2007-05-23 Tsz Ho Chan

We show the existence of ``good'' approximations to a real number $\gamma$ using rationals with denominators formed by digits $0$ and $1$ in base $b$. We derive an elementary estimate and enhance this result by managing exponential sums.

Number Theory · Mathematics 2025-03-04 Siddharth Iyer

The papers shows an algorithm to search for approximations of reals to rationals of the form a/b^2 that runs on \sqrt(b) polynomial time steps.

Number Theory · Mathematics 2007-05-23 I. Jimenez Calvo

We present a complete algorithm for finding an exact minimal polynomial from its approximate value by using an improved parameterized integer relation construction method. Our result is superior to the existence of error controlling on…

Symbolic Computation · Computer Science 2010-01-06 Xiaolin Qin , Yong Feng , Jingwei Chen , Jingzhong Zhang

We present a new algorithm for reconstructing an exact algebraic number from its approximate value using an improved parameterized integer relation construction method. Our result is consistent with the existence of error controlling on…

Computational Complexity · Computer Science 2009-02-06 Xiaolin Qin , Yong Feng , Jingwei Chen , Jingzhong Zhang

We describe an approximate rational arithmetic with round-off errors (both absolute and relative) controlled by the user. The rounding procedure is based on the continued fraction expansion of real numbers. Results of computer experiments…

Numerical Analysis · Mathematics 2025-10-20 Grigori Litvinov , Anatoli Rodionov , Andrei Chourkin

Following T. H. Chan, we consider the problem of approximation of a given rational fraction a/q by sums of several rational fractions a_1/q_1, ..., a_n/q_n with smaller denominators. We show that in the special cases of n=3 and n=4 and…

Number Theory · Mathematics 2007-07-24 Igor E. Shparlinski

We consider the problem of approaching real numbers with rational numbers with prime denominator and with a single numerator allowed for each denominator. We then present a simple application, related to possible correlations between trace…

Number Theory · Mathematics 2023-09-26 Emmanuel Kowalski

We consider the problem of approaching real numbers with rational numbers with prime denominator and with a single numerator allowed for each denominator. We obtain basic results, both probabilistic and deterministic, draw connections to…

Number Theory · Mathematics 2025-11-21 Manuel Hauke , Emmanuel Kowalski

Given any polynomial with real coefficients, the existence of a real quadratic polynomial factor is proven using only basic real analysis. The aim is to provide an approachable proof to anybody who is familiar with the least upper bound…

Classical Analysis and ODEs · Mathematics 2020-09-28 Soham Basu

We provide the detailed proof of a strengthened version of the M. Artin Approximation Theorem.

Complex Variables · Mathematics 2015-05-19 Arkadiusz Ploski

Numerical approximate computation can solve large and complex problems fast. It has the advantage of high efficiency. However it only gives approximate results, whereas we need exact results in many fields. There is a gap between…

Algebraic Geometry · Mathematics 2015-06-26 Jingzhong Zhang , Yong Feng

In this paper we prove that all irrational numbers from totally real cubic number fields are well approximable by rationals (i.e. the partial quotients in the continued fraction expansion of such a number are unbounded). This settles the…

Number Theory · Mathematics 2023-10-24 Alan Haynes

In this paper we describe an algorithm for implicitizing rational hypersurfaces in case there exists at most a finite number of base points. It is based on a technique exposed in math.AG/0210096, where implicit equations are obtained as…

Algebraic Geometry · Mathematics 2007-05-23 Laurent Buse , Marc Chardin
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