Search results for " Mathematics"

Unification in superintuitionistic predicate logics and its applications

2018

AbstractWe introduce unification in first-order logic. In propositional logic, unification was introduced by S. Ghilardi, see Ghilardi (1997, 1999, 2000). He successfully applied it in solving systematically the problem of admissibility of inference rules in intuitionistic and transitive modal propositional logics. Here we focus on superintuitionistic predicate logics and apply unification to some old and new problems: definability of disjunction and existential quantifier, disjunction and existential quantifier under implication, admissible rules, a basis for the passive rules, (almost) structural completeness, etc. For this aim we apply modified specific notions, introduced in proposition…

Generalized Weyl's theorem and quasi-affinity

2010

Group Actions and Asymptotic Behavior of Graded Polynomial Identities

2002

G. Birkhoff's theorems for M -solid varieties

1998

Our aim is to prove two Birkhoff's like theorems for M-solid varieties of algebras, invented in [10], [11], generalizing some results of [5]. They have been presented on the Fifth Mathematical Conference "Workshop 97" at Gronow, Poland on June 27, 1997.

Groups with exactly one irreducible character of degree divisible byp

2014

Let [math] be a prime. We characterize those finite groups which have precisely one irreducible character of degree divisible by [math] .

Symmetric Surfaces with Many Singularities

2004

Abstract Let G ⊂ SO(4) denote a finite subgroup containing the Heisenberg group. In this paper we classify all such groups, we find the dimension of the spaces of G-invariant polynomials and we give equations for the generators whenever the space has dimension two. Then we complete the study of the corresponding G-invariant pencils of surfaces in ℙ3 which we started in Sarti [Sarti, A. (2000). Pencils of symmetric surfaces in ℙ3(C). J. Algebra 246:429–452]. It turns out that we have five more pencils, two of them containing surfaces with nodes.

Generalizations of Clausen's formula and algebraic transformations of Calabi-Yau differential equations

2011

AbstractWe provide certain unusual generalizations of Clausen's and Orr's theorems for solutions of fourth-order and fifth-order generalized hypergeometric equations. As an application, we present several examples of algebraic transformations of Calabi–Yau differential equations.

Examples of improjective operators

2000

It has been an open question for some time whether improjective operators are always inessential. Here we give some examples that answer in the negative this question as well as some other related ones, posed in [2, 3, 11, 12]. The description of the examples uses a indecomposable space, constructed by Gowers and Maurey [5], and a characterization of the indecomposable Banach spaces in terms of improjective operators.

Large orbits ofp-groups on characters and applications to character degrees

2005

We prove that if ap-groupA acts on a solvablep′-groupG then there is a “large” orbit on the ordinary complex irreducible characters ofG. As a consequence of this theorem we obtain results that relate ordinary and Brauer character degrees.

Equivariant algebraic vector bundles over cones with smooth one dimensional quotient

1998