Search results for "MATHEMATICS"
showing 10 items of 22031 documents
Recovering a variable exponent
2021
We consider an inverse problem of recovering the non-linearity in the one dimensional variable exponent $p(x)$-Laplace equation from the Dirichlet-to-Neumann map. The variable exponent can be recovered up to the natural obstruction of rearrangements. The main technique is using the properties of a moment problem after reducing the inverse problem to determining a function from its $L^p$-norms.
Very narrow quantum OBDDs and width hierarchies for classical OBDDs
2014
In the paper we investigate a model for computing of Boolean functions - Ordered Binary Decision Diagrams (OBDDs), which is a restricted version of Branching Programs. We present several results on the comparative complexity for several variants of OBDD models. - We present some results on the comparative complexity of classical and quantum OBDDs. We consider a partial function depending on a parameter k such that for any k > 0 this function is computed by an exact quantum OBDD of width 2, but any classical OBDD (deterministic or stable bounded-error probabilistic) needs width 2 k+1. - We consider quantum and classical nondeterminism. We show that quantum nondeterminism can be more efficien…
On partially saturated formations of finite groups.
2007
This thesis deals with finite groups. More precisely, it studies formations,which are classes of groups closed under taking homomorphic images andsubdirect products. The concept of X-local formation, where X is a classof simple groups, generalises the concepts of local formation and Baer-localformation. It was introduced by F¨orster with the aim of generalising thewell-known theorems of Gasch¨utz-Lubeseder-Schmid and Baer. The first onestates that a formation is saturated if and only if it is local. The second onecharacterises Baer-local formations as the solubly saturated ones. F¨orsterintroduced a Frattini-like subgroup associated with the class X and whichallowed him to introduce the con…
Problem Talk in Management Group Meetings
2019
This naturalistic study focuses on problem talk (PT) in hospital management group meetings. The study aims to understand how PT constitutes the hospital organization through the different uses of PT within the meetings, and, therefore, to understand the organizing role of these meetings. The communication as constitutive of organization (CCO) perspective forms the theoretical background of the research. The results of the qualitative analysis show that PT comprises many intertwined tasks that aim to perform the meetings, enhance problem solving, and maintain the relational level of group life. Thus, PT is much more than merely solving problems. In PT, problems are discussed from the viewpo…
Non-homogeneous Dirichlet problems with concave-convex reaction
2022
The variational methods are adopted for establishing the existence of at least two nontrivial solutions for a Dirichlet problem driven by a non-homogeneous differential operator of p-Laplacian type. A large class of nonlinear terms is considered, covering the concave-convex case. In particular, two positive solutions to the problem are obtained under a (p -1)-superlinear growth at infinity, provided that a behaviour less than (p -1)-linear of the nonlinear term in a suitable set is requested.
Solutions with sign information for nonlinear Robin problems with no growth restriction on reaction
2019
We consider a parametric nonlinear Robin problem driven by a nonhomogeneous differential operator. The reaction is a Carathéodory function which is only locally defined (that is, the hypotheses concern only its behaviour near zero). The conditions on the reaction are minimal. Using variational tools together with truncation, perturbation and comparison techniques and critical groups, we show that for all small values of the parameter λ > 0, the problem has at least three nontrivial smooth solutions, two of constant sign and the third nodal.
On the CAT(0) dimension of 2-dimensional Bestvina-Brady groups
2002
Let K be a 2-dimensional finite flag complex. We study the CAT(0) dimension of the `Bestvina-Brady group', or `Artin kernel', Gamma_K. We show that Gamma_K has CAT(0) dimension 3 unless K admits a piecewise Euclidean metric of non-positive curvature. We give an example to show that this implication cannot be reversed. Different choices of K lead to examples where the CAT(0) dimension is 3, and either (i) the geometric dimension is 2, or (ii) the cohomological dimension is 2 and the geometric dimension is not known.
The Bishop-Phelps-Bollobás property for bilinear forms and polynomials
2014
For a $\sigma$-finite measure $\mu$ and a Banach space $Y$ we study the Bishop-Phelps-Bollobás property (BPBP) for bilinear forms on $L_1(\mu)\times Y$, that is, a (continuous) bilinear form on $L_1(\mu)\times Y$ almost attaining its norm at $(f_0,y_0)$ can be approximated by bilinear forms attaining their norms at unit vectors close to $(f_0,y_0)$. In case that $Y$ is an Asplund space we characterize the Banach spaces $Y$ satisfying this property. We also exhibit some class of bilinear forms for which the BPBP does not hold, though the set of norm attaining bilinear forms in that class is dense.
Nome e numero: una parentela.
2014
In this paper we describe the relationships between two fundamental “cognitive gestures” of human beings: naming and counting. In particular, we try to define these relationships by examining the theoretical efforts of such authors as Euclide, Frege, Wittgenstein, Chomsky and Aristotle. The analysis is centered around justifying the mutual dependence between noun and number in human cognition.
Families of solutions to the KPI equation and the structure of their rational representations of order N
2018
We construct solutions to the Kadomtsev-Petviashvili equation (KPI) in terms of Fredholm determinants. We deduce solutions written as a quotient of wronskians of order 2N. These solutions called solutions of order N depend on 2N − 1 parameters. They can also be written as a quotient of two polynomials of degree 2N (N + 1) in x, y and t depending on 2N − 2 parameters. The maximum of the modulus of these solutions at order N is equal to 2(2N + 1) 2. We explicitly construct the expressions until the order 6 and we study the patterns of their modulus in the plane (x, y) and their evolution according to time and parameters.