Imaginary quadratic fields with small odd class number
Implementing 2-descent for Jacobians of hyperelliptic curves
Implementing the Round Four maximal order algorithm
Improvements on the Cantor-Zassenhaus factorization algorithm
The paper presents a careful analysis of the Cantor-Zassenhaus polynomial factorization algorithm, thus obtaining tight bounds on the performances, and proposing useful improvements. In particular, a new simplified version of this algorithm is described, which entails a lower computational cost. The key point is to use linear test polynomials, which not only reduce the computational burden, but can also provide good estimates and deterministic bounds of the number of operations needed for factoring....
Incomplete character sums over finite fields and their application to the interpolation of the discrete logarithm by Boolean functions
Increasing integer sequences and Goldbach's conjecture
Increasing integer sequences include many instances of interesting sequences and combinatorial structures, ranging from tournaments to addition chains, from permutations to sequences having the Goldbach property that any integer greater than 1 can be obtained as the sum of two elements in the sequence. The paper introduces and compares several of these classes of sequences, discussing recurrence relations, enumerative problems and questions concerning shortest sequences.
Index form equations in quintic fields
The problem of determining power integral bases in algebraic number fields is equivalent to solving the corresponding index form equations. As is known (cf. Győry [25]), every index form equation can be reduced to an equation system consisting of unit equations in two variables over the normal closure of the original field. However, the unit rank of the normal closure is usually too large for practical use. In a recent paper Győry [27] succeeded in reducing index form equations to systems of unit...
Index form equations in sextic fields: a hard computation
Inequalities for the Landau constants
Influence of modeling structure in probabilistic sequential decision problems
Markov Decision Processes (MDPs) are a classical framework for stochastic sequential decision problems, based on an enumerated state space representation. More compact and structured representations have been proposed: factorization techniques use state variables representations, while decomposition techniques are based on a partition of the state space into sub-regions and take advantage of the resulting structure of the state transition graph. We use a family of probabilistic exploration-like...
Integral minimalisations improvement for Murphy's polynomial selection algorithm.
Integral points on elliptic curves defined by simplest cubic fields.
Integral points on the elliptic curve
Let be a fixed odd prime. We combine some properties of quadratic and quartic Diophantine equations with elementary number theory methods to determine all integral points on the elliptic curve . Further, let denote the number of pairs of integral points on with . We prove that if , then or depending on whether or .
Integrals of logarithmic and hypergeometric functions
Integrals of logarithmic and hypergeometric functions are intrinsically connected with Euler sums. In this paper we explore many relations and explicitly derive closed form representations of integrals of logarithmic, hypergeometric functions and the Lerch phi transcendent in terms of zeta functions and sums of alternating harmonic numbers.
Involutions Associated With Sums of two Squares
Isomorphisms of algebraic number fields
Let and be algebraic number fields. We describe a new method to find (if they exist) all isomorphisms, . The algorithm is particularly efficient if there is only one isomorphism.
Iterating the sum-of-divisors function.