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Displaying 941 – 960 of 1970

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A strengthening of the Nyman-Beurling criterion for the Riemann hypothesis

Luis Báez-Duarte (2003)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

According to the well-known Nyman-Beurling criterion the Riemann hypothesis is equivalent to the possibility of approximating the characteristic function of the interval 0 , 1 in mean square norm by linear combinations of the dilations of the fractional parts 1 / a ⁢ x for real a greater than 1 . It was conjectured and established here that the statement remains true if the dilations are restricted to those where the a ’s are positive integers. A constructive sequence of such approximations is given.

A structure theorem for sets of small popular doubling

Przemysław Mazur (2015)

Acta Arithmetica

We prove that every set A ⊂ ℤ satisfying ∑ x m i n ( 1 A * 1 A ( x ) , t ) ≤ ( 2 + δ ) t | A | for t and δ in suitable ranges must be very close to an arithmetic progression. We use this result to improve the estimates of Green and Morris for the probability that a random subset A ⊂ ℕ satisfies |ℕ∖(A+A)| ≥ k; specifically, we show that ℙ ( | ℕ ∖ ( A + A ) | ≥ k ) = Θ ( 2 - k / 2 ) .

A study of the mean value of the error term in the mean square formula of the Riemann zeta-function in the critical strip 3 / 4 ≤ σ < 1

Yuk-Kam Lau (2006)

Journal de Théorie des Nombres de Bordeaux

Let E σ ( T ) be the error term in the mean square formula of the Riemann zeta-function in the critical strip 1 / 2 < σ < 1 . It is an analogue of the classical error term E ( T ) . The research of E ( T ) has a long history but the investigation of E σ ( T ) is quite new. In particular there is only a few information known about E σ ( T ) for 3 / 4 < σ < 1 . As an exploration, we study its mean value ∫ 1 T E σ ( u ) d u . In this paper, we give it an Atkinson-type series expansion and explore many of its properties as a function of T .

A subresultant theory of multivariate polynomials.

Laureano González Vega (1990)

Extracta Mathematicae

In Computer Algebra, Subresultant Theory provides a powerful method to construct algorithms solving problems for polynomials in one variable in an optimal way. So, using this method we can compute the greatest common divisor of two polynomials in one variable with integer coefficients avoiding the exponential growth of the coefficients that will appear if we use the Euclidean Algorithm.In this note, generalizing a forgotten construction appearing in [Hab], we extend the Subresultant Theory to the...

A survey of computational class field theory

Henri Cohen (1999)

Journal de théorie des nombres de Bordeaux

We give a survey of computational class field theory. We first explain how to compute ray class groups and discriminants of the corresponding ray class fields. We then explain the three main methods in use for computing an equation for the class fields themselves: Kummer theory, Stark units and complex multiplication. Using these techniques we can construct many new number fields, including fields of very small root discriminant.

Currently displaying 941 – 960 of 1970