: The vise tightens. (Ensembles : L'étau se resserre.)
Let and be the Lucas sequences of the first and second kind respectively at the parameters and . In this paper, we provide a technique for characterizing the solutions of the so-called Bartz-Marlewski equation where or with , . Then, the procedure of this technique is applied to completely resolve this equation with certain values of such parameters.
Let K = Q(ζp) and let hp be its class number. Kummer showed that p divides hp if and only if p divides the numerator of some Bernoulli number. In this expository note we discuss the generalizations of this type of criterion to totally real fields and quadratic imaginary fields.
Let be a real algebraic number of degree over whose conjugates are not real. There exists an unit of the ring of integer of for which it is possible to describe the set of all best approximation vectors of .’