Le Matematiche  

Andrea Lucchini, M. Chiara Tamburini

Let H be a nilpotent subgroup of GL_n (q) = <f> GL_n (q), where f denotes the field automorfism induced by the Frobenius map. We give a condition on the primes dividing |H n GL_n (q)| under which H is conjugate to a subgroup of the generalized monom... see more

Thomas Bieske

We employ Riemannian jets which are adapted to the Riemannian geometry to obtain the existence-uniqueness of in?nite harmonic functions in Riemannian spaces. We then show such functions are equivalent to those that enjoy comparison with Riemannian cones. ... see more

Maria Scafati Tallini, Maurizio Iurlo

We study a remarkable class of rings, which we call corpids, that is the rings, different from zero, (K;+; .); such that (K; .) is an inverse semi-group (or groupid, which is the name given by G. Tallini [4]). The inverse semigroup has been de?ned and cal... see more

Rachid Choukri, Abdellah El Kinani

We give a complete characterization of Q-F-algebras A which satisfy Ax = xAx for every x in A.

Mehmet Ali Gungor, Murat Tosun

In this work, we ?rst introduced one parameter dual Lorentzian spherical motions in three dimensional dual Lorentz space D^3_1 and spacelikeand timelike ruled surfaces in three dimensional Lorentz space IR^3_1 corresponding to dual curves on dual Lorentz ... see more

Barbara Brandolini, Carlo Nitsch, Paolo Salani, Cristina Trombetti

We investigate the stability of the radial symmetry for the overdetermined Serrin problem in a planar convex set. More precisely, we prove that, whenever we properly perturb both the boundary conditions and the data, then a convex solution is “close” to a... see more

Calogero Vetro

In this paper we introduce the notion of g-weak isotone mappings in an ordered Banach space and we extend some common ?xed point theorems of Dhage, O’Regan and Agarwal [1].

Albo Carlos Cavalheiro

In this paper we are interested in the existence of solutions for Dirichlet problem associated to the degenerate quasilinear elliptic equations 

Giuseppe Bilotta

Le MatematicheVol. LXIII (2008 - Fasc. I, pp. 15–30)For a technical mistake this article appeared without references and citations. Here we add the references and, page by page, the necessary citations in order of appearance. We apologize for this inconve... see more

Jurgen Herzog, Volkmar Welker

The subsequent papers are based on results obtained during or in the sequel of the Pragmatic School 2008. The school was held from July 14 till August 1, 2009 on the campus of the University of Catania. It was devoted to combinatorial aspects of commutati... see more

Bruno Benedetti, Alexandru Constatinescu, Matteo Varbaro

We study the basic k-covers of a bipartite graph G; the algebra A(G) they span, first studied by Herzog, is the fiber cone of the Alexander dual of the edge ideal. We characterize when A(G) is a domain in terms of the combinatorics of G; it follows from a... see more

Cristina Bertone, Vincenzo Micale

In a paper in 2008, Herzog, Hibi and Ohsugi introduced and studied the semigroup ring associated to the set of minimal vertex covers of an unmixed bipartite graph. In this paper we relate the dimension of this semigroup ring to the rank of the Boolean lat... see more

Mircea Cimpoeas

We show that Stanley’s conjecture holds for any multigraded module M over S, with sdepth(M) = 0, where S = K[x_1; ... ; x_n]. Also, we give some bounds for the Stanley depth of the powers of the maximal irrelevant ideal in S.

Alexandru Costantinescu, Le Dinh Nam

In [5] the authors characterize the vertex cover algebras which are tandard graded. In this paper we give a simple combinatorial criterion for the standard graded property of vertex cover algebras in the case of quasi-trees. We also give an example of how... see more

Veronica Crispin, Eric Emtander

Let G be a simple undirected graph on n vertices. Francisco and VanTuyl have shown that if G is chordal ...

Gioia Failla, Monica La Barbiera, Paola L. Staglianò

Let A=K[x1, ..... ,xn] be a standard graded polynomial ring over a ?eld K, let M = (x_1, .... , x_n) be the graded maximal ideal and I a graded ideal of A. For each i the Betti numbers b_i(I^k ) of I^k are polynomial functions for k>>0. We... see more

Gesa Kampf, Martina Kubitzke

We survey and compare invariants of modules over the polynomial ring and the exterior algebra. In our considerations, we focus on the depth. The exterior analogue of depth was ?rst introduced by Aramova, Avramov and Herzog. We state similarities between t... see more

Benjamin Nill, Kathrin Vorwerk

A famous conjecture by R. Stanley relates the depth of a module, an algebraic invariant, with the so-called Stanley depth, a geometric one. We describe two related geometric notions, the cover depth and the greedy depth, and we study their relations with ... see more

Anda Olteanu, Oana Olteanu, Loredana Sorrenti

In this paper we characterize the componentwise lexsegment ideals which are componentwise linear and the lexsegment ideals generated in one degree which are Gotzmann.

Giancarlo Rinaldo

In this article we describe an algorithm to compute the Stanley depth of I=J where I and J are monomial ideals. We describe also an implementation in CoCoA.

Leila Sharifan, Matteo Varbaro

In this paper we show that every ideal with linear quotients is componentwise linear. We also generalize the Eliahou-Kervaire formula for graded Betti numbers of stable ideals to homogeneous ideals with linear quotients.