Irreducible p-constant characters of finite reflection groups

A complex irreducible character of a finite group G is said to be p-constant, for some prime p dividing the order of G, if it takes constant value at the set of p-singular elements of G. In this paper we classify irreducible p-constant characters for finite reflection groups, nilpotent groups and complete monomial groups. We also propose some conjectures about the structure of the groups admitting such characters.Comment: To appear in Journal of Group Theor

The (2,3)-generation of the special linear groups over finite fields

We complete the classification of the finite special linear groups \SL_n(q) which are $(2,3)$-generated, i.e., which are generated by an involution and an element of order $3$. This also gives the classification of the finite simple groups \PSL_n(q) which are $(2,3)$-generated.Comment: 5 page

The (2,3)-generation of the classical simple groups of dimension 6 and 7

In this paper we prove that the finite simple groups $PSp_6(q)$, $\Omega_7(q)$ and $PSU_7(q^2)$ are (2,3)-generated for all q. In particular, this result completes the classification of the (2,3)-generated finite classical simple groups up to dimension 7

A generalization of the problem of Mariusz Meszka

Mariusz Meszka has conjectured that given a prime p=2n+1 and a list L containing n positive integers not exceeding n there exists a near 1-factor in K_p whose list of edge-lengths is L. In this paper we propose a generalization of this problem to the case in which p is an odd integer not necessarily prime. In particular, we give a necessary condition for the existence of such a near 1-factor for any odd integer p. We show that this condition is also sufficient for any list L whose underlying set S has size 1, 2, or n. Then we prove that the conjecture is true if S={1,2,t} for any positive integer t not coprime with the order p of the complete graph. Also, we give partial results when t and p are coprime. Finally, we present a complete solution for t<12.Comment: 15 page

Tandem Repeats in Proteins: Prediction Algorithms and Biological Role

Tandem repetitions in protein sequence and structure is a fascinating subject of research which has been a focus of study since the late 1990s. In this survey, we give an overview on the multi-faceted aspects of research on protein tandem repeats (PTR for short), including prediction algorithms, databases, early classification efforts, mechanisms of PTR formation and evolution, and synthetic PTR design. We also touch on the rather open issue of the relationship between PTR and flexibility (or disorder) in proteins. Detection of PTR either from protein sequence or structure data is challenging due to inherent high (biological) signal-to-noise ratio that is a key feature of this problem. As early in silico analytic tools have been key enablers for starting this field of study, we expect that current and future algorithmic and statistical breakthroughs will have a high impact on the investigations of the biological role of PTR

On computing the diameter of a point set in high dimensional Euclidean space

We consider the problem of computing the diameter of a set of $n$ points in $d$-dimensional Euclidean space under Euclidean distance function. We describe an algorithm that in time $O(dnlog n +n^{2})$ finds with high probability an arbitrarily close approximation of the diameter. For large values of $d$ the complexity bound of our algorithm is a substantial improvement over the complexity bounds of previously known exact algorithms. Computing and approximating the diameter are fundamental primitives in high dimensional computational geometry and find practical application, for example, in clustering operations for image databases

IL "BUSINESS MODEL" NELLA COMUNICAZIONE ECONOMICO-FINANZIARIA. UN'ANALISI DELLE SOCIETA' QUOTATESI DAL 2006 AL 2011 SULL'M.T.A. DI BORSA ITALIANA

Il presente lavoro è nato con l'obiettivo di mettere in evidenza il livello delle informazioni riguardanti il "Business Model" all'interno dei principali documenti societari, ovvero del Prospetto Informativo e del Bilancio Consolidato. Come modello per condurre la nostra ricerca è stato utilizzato il QMAT di Borsa Italiana da cui abbiamo derivato la griglia di analisi, da applicare al campione selezionato, composto da 33 società che si sono quotate sull'MTA di Borsa Italiana dal 2006 al 2011. La descrizione della ricerca e l'analisi dei risultati è però preceduta da due capitoli in cui, nel primo, è stato definito e approfondito il concetto di business model mentre, nel secondo, è stato affrontato il tema della comunicazione economico-finanziaria, con la presentazione dettagliata dei documenti utilizzati nel presente studio

Local field enhancement: comparing self-similar and dimer nanoantennas

We study the local field enhancement properties of self-similar nanolenses and compare the obtained results with the performance of standard dimer nanoantennas. We report that, despite the additional structural complexity, self-similar nanolenses are unable to provide significant improvements over the field enhancement performance of standard plasmonic dimers

Fine structure of the confining string in an analytically solvable 3D model

In $\mathrm{U(1)}$ lattice gauge theory in three spacetime dimensions, confinement can be analytically shown to persist at all values of the coupling. Furthermore, the explicit predictions for the dependence of string tension $\sigma$ and mass gap $m_0$ on the coupling allow one to tune their ratio at will. These features, and the possibility of obtaining high-precision numerical results via an exact duality map to a spin model, make this theory an ideal laboratory to test the effective string description of confining flux tubes. In this contribution, we discuss our investigation of next-to-leading-order corrections to the confining potential and of the finite-temperature behavior of the flux tube width. Our data provide a very stringent test of the theoretical predictions for these quantities and allow to test their dependence on the $m_0/\sqrt{\sigma}$ ratio.Comment: Presented at the 31st International Symposium on Lattice Field Theory (Lattice 2013), 29 July - 3 August 2013, Mainz, German