Showing papers in "Annali Dell'universita' Di Ferrara in 1982"
TL;DR: In this article, a variational problem for a functional with a characteristic function term which causes the free boundary is treated, and the regularity of minimizers in the radially symmetric case is investigated.
Abstract: We treat a variational problem for a functional with a characteristic function term which causes the free boundary, and investigate the regularity of minimizers in the radially symmetric case The regularity results depend upon the quantity of the coefficient of the term
6 citations
TL;DR: In this paper, it was shown that l'insieme delle funzioni analitiche suX and denso, nella topologia di Whitney, nello spazio dell'C∞ suX.
Abstract: Sia (X, OX) uno spazio analitico reale che sia la parte reale di uno spazio analitico complesso. Si prova che l'insieme delle funzioni analitiche suX e denso, nella topologia di Whitney, nello spazio delle funzioniC∞ suX.
4 citations
TL;DR: A subschemeX⊂Y is an asimple intersection of hypersurfaces (effective Cartier divisors) as discussed by the authors, where X is the intersection of F 1, …,F m.
Abstract: A subschemeX⊂Y is asimple intersection of hypersurfaces (effective Cartier divisors)F 1,…,F m ofY ifX is the intersection subscheme ofF 1, …,F m.
4 citations
3 citations
TL;DR: In this article, the authors considered second order weakly hyerbolic equations with Lipschitz or Holder continuous coefficients with respect to time concerning the well posedness of the Cauchy problem and the propagation of the singularities in the framework of Gevrey classes.
Abstract: We consider second order weakly hyerbolic equations, with Lipschitz or Holder continuous coefficients with respect to time, concerning the well posedness of the Cauchy problem and the propagation of the singularities in the framework of Gevrey classes.
2 citations
2 citations
TL;DR: In this article, the passaggio di condizioni di fattorialita (i.e., UFD and semi-finalita) daG adR, daR adA, and viceversa is studied.
Abstract: Dato un anello noetherianoA, sianoG(A,α) il graduato diA, associato ad un suo ideale α, edR(A,α) l'algebra di Rees estesa diA associata ad α In questa Nota si studia il passaggio di condizioni di fattorialita (ie: UFD e semifattorialita) daG adR, daR adA e viceversa
2 citations
2 citations
TL;DR: In this paper, a studio in meccanica quantistica di una particella in un campo magneticoB nel caso particolareB=B(x,y)e3 si interpretare, in modo naturale, a meno di a transformata di Fourier, come deformazione of una ipersuperficie reale nello spazio di due variabili complesse.
Abstract: Lo studio in meccanica quantistica di una particella in un campo magneticoB nel caso particolareB=B(x,y)e3 si puo interpretare, in modo naturale, a meno di una transformata di Fourier, come deformazione di una ipersuperficie reale nello spazio di due variabili complesse. Le prime autofunzioni corrispondono alle funzioni di Cauchy-Riemann. Cio consente di calcolare esplicitamente degli autovalori di operatori sul gruppo di Heisenberg.
1 citations
1 citations
TL;DR: In this paper, the Hartshorne-Rao module of integral subcanonical curves and the first cohomology module for rank two vector bundles on projective space were shown to be connected.
Abstract: We provide sufficient conditions for the connectedness of the Hartshorne-Rao module of integral subcanonical curves and of the first cohomology module for rank two vector bundles on projective space.
TL;DR: In this article, the Neron Severi group is used to define the Birational structure of the irreducible components of the components of suitable M(S, 2,H, L, t)red withS a relatively minimal model of X.
Abstract: Here we prove the following result. Fix integersq, τ,a’, b’, a’i, 1≤i≤τ,a’, b’, a’i, 1≤i≤τ; then there is an integerew such that for every integert≥w, for every algebraically closed fieldK for every smooth complete surfaceX with negative Kodaira dimension, irregularityq andKX2=8(1−q)−τ, the following condition holds; ifX→S is a sequence fo τ blowing-downs which gives a relatively minimal model with ruling ρ:S→C, take as basis of the Neron Severi groupNS(X) a smooth rational curve which is the total transform of a fiber ofC, the total transform of a minimal section of ρ and the total transformDi, 1≤i≤τ, of the exceptional curver; then for everyH andL∈Pic (X) withH ample,H (resp.L) represented by the integersa’, b’, a’i, (resp.a’, b’, a’i), 1≤i≤τ, in the chosen basis ofNS(X) the moduli spaceM(ZX, 2,H, L, t) of rank 2H-stable vector bundles onX with determinantL andc2=t is generically smooth and the number, dimension and «birational structure» of the irreducible components ofM(X, 2,H, L, t)red do not depend on the choice ofK andX. Furthermore the birational structure of these irreducible components can be loosely described in terms of the birational structure of the components of suitableM(S, 2,H’, L’, t’)red withS a relatively minimal model ofX.
TL;DR: In this article, studiano stabilita, categoricita, and eliminazione dei quantificatori per una classe di anelli locali that possono essere considerati, da un punto di vista intuitivo, as ''campi con infinitesimi''.
Abstract: Si studiano stabilita, categoricita ed eliminazione dei quantificatori per una classe di anelli locali che possono essere considerati, da un punto di vista intuitivo, come «campi con infinitesimi».
TL;DR: In this paper, the authors consider the problem of finding the dominant map between real algebraic varieties of the same dimension, which is the map which sends every pointy ∈ Y to the number of real points inf − 1 (y) and give a sufficient condition ony to ensure that the above map is locally constant.
Abstract: Letf: X → Y be a dominant map between real algebraic varieties of the same dimension. The object of this paper is the study of the map which sends every pointy ∈ Y to the number of real points inf
−1 (y). We give a sufficient condition ony to ensure that the above map is locally constant iny. Moreover, we consider the subset ofY where this map is no more locally constant and we give the principal properties of this set.
TL;DR: In this paper, it was shown that there exists a valuation domain A, having an ideal which cannot be generated by a countable set of elements, and such that its field of quotients has homological dimension 1.
Abstract: In [3], Anne MarieNicolas asked the following question: Does there exist a valuation domainA, having an ideal which cannot be generated by a countable set of elements, and such that its field of quotients has homological dimension 1? We answer this question in the affirmative
TL;DR: In this paper, the same authors prove some theorems of global attractivity and total stability for a setM of R n with respect to the solutions of a differential equation, employing the limiting equations associated to the given equation.
Abstract: We prove some theorems of global attractivity and total stability for a setM ofR
n, with respect to the solutions of a differential equation, employing the limiting equations associated to the given equation.
TL;DR: In this article, the problem of determinazione della topologia delle curve algebriche reali is solved for curve di gradom, conm≤7.
Abstract: Il problema posto da Hilbert (XVI problema), della determinazione della topologia delle curve algebriche reali e risolto completamente solo per curve di gradom, conm≤7.
TL;DR: In this article, the authors studied the initial boundary value problem in bounded domains, where they proved global existence of weak solutions for the dynamics and for the thermodynamics of the system for k-polar materials with k t > 3.
Abstract: Physical background to the thermoviscoelastic multipolar materials is studied in Ne6as, R~i6ka[1]. These materials seem better to describe real situations in the case when the dissipation plays substantial role. Our article deals with adequate mathematical theory. We study the initial boundary value problem in bounded domains, where we prove global existence of weak solutions for the dynamics (Theorem 4.2) and for the thermodynamics (Theorem 4.7) of the system for k-polar materials with k t> 3. We are also dealing with the regularity up to the strong solutions in dependence on regularity of initial data (Theorem 4.7). For the proof standard method of compactness is used (see e.g. Lions [9]).
TL;DR: In this paper, a space of harmonic functions defined in Lipschitz domains is introduced, and it is shown that such functions characterize all the Poisson integrals of functions with vanishing mean oscillation.
Abstract: In this paper we introduce a space of harmonic functions defined in Lipschitz domains and we show that such a functions characterize all the Poisson integrals of functions with vanishing mean oscillation.
TL;DR: In this article, the existence of homoclinic orbits for the second order conservative systems was studied under some conditions, where the set Ω = {x ∈ R n ;V(x) < 0} is unbounded and Ω(R^n \backslash \bar \Omega ≠ 0.
Abstract: This paper deals with the existence of homoclinic orbits for the second order conservative systems:
$$\ddot q + V'\left( q \right) = 0$$
under some conditions. When the setΩ = {x ∈R n ;V(x) < 0} is unbounded and\(R^n \backslash \bar \Omega \) ≠ 0, the paper extends some previous results.
TL;DR: Vengono discusse alcune proprieta deip T.I.-gruppi (p primo dispari), cioe gruppi in which due Sylowp-sottogruppi distinti hanno intersezione ridotta a {1}, nel caso in cui Op'(CG(P)) sia ciclico di ordine 2,P SylowP-sophogruppo diG eNG(P)=GG(Op'( CG(P)).
Abstract: Vengono discusse alcune proprieta deip T.I.-gruppi (p primo dispari), cioe gruppi in cui due Sylowp-sottogruppi distinti hanno intersezione ridotta a {1}, nel caso in cuiOp'(CG(P)) sia ciclico di ordine 2,P Sylowp-sottogruppo diG eNG(P)=GG(Op'(CG(P))).
TL;DR: A compactness theorem for weighted Sobolev spaces in R n without requiring that the weight function to be infinite at infinity was proved in this paper, which generalizes some recent results of V. Benci and D. Fortunato.
Abstract: A compactness theorem for weighted Sobolev spaces inR n is proved, without requiring that the weight function to be infinite at infinity. The theorem generalizes some recent results ofV. Benci andD. Fortunato [3].
TL;DR: In this article, the orthogonal group of a diagonal quadratic space of rank 2 on P.I.D. is characterized and criterions such that two diagonals quadrastic spaces of rank two are isometric.
Abstract: On caracterise le groupe orthogonal d’un espace quadratique diagonal de rang 2 sur un anneau principal; on donne des criteres pour que deux espces quadratiques diagonaux de rang 2 soient isometriques. We characterize the orthogonal group of a diagonal quadratic space of rank 2 on P.I.D.; we give criterions such that two diagonals quadratic spaces of rank 2 are isometric.
TL;DR: In this paper, the authors studied an elastic membrane with fixed rim and proved a theorem of existence and regularity of a minimum for the total energy of this system when gravity is small and a monotonic dependance of the height of the barycentre of the body with respect to the change of the gravity.
Abstract: The subject of this paper is the study of an elastic membrane with fixed rim. This membrane has to hold a heavy stiff body. We prove a theorem of existence and regularity of a minimum for the total energy of this system when gravity is small. Moreover we prove a monotonic dependance of the height of the barycentre of the body with respect to the change of the gravity.
TL;DR: The orthogonal decomposition of an energetic Hilbert space over some open (not necessarily bounded) domain with piecewise smooth boundary in two- or three-dimensional Euclidean space was studied in this article.
Abstract: The orthogonal decompositions\(\mathop D\limits^ \circ = H \oplus P \oplus F, H \oplus P = H\), and\(P \oplus F = F\) are established, where\(\mathop D\limits^ \circ \) is an energetic Hilbert space over some open (not necessarily bounded) domain with piecewise smooth boundary in two- or three-dimensional Euclidean space. An intrinsic characterization of the subspacesH, P andF is given as well.
TL;DR: In this article, a modello cinematico di incrudimento di Prager ai corpi elastoplastici tridimensionali, nell'ipotesi di deformazioni infinitesime, is described.
Abstract: In questo lavoro si e esteso il modello cinematico di incrudimento di Prager ai corpi elastoplastici tridimensionali, nell'ipotesi di deformazioni infinitesime [2]. Scopo del lavoro e mostrare che il modello di materiale elastoplastico che veniamo a costruire e un sistema secondo la definizione data da Coleman e Owen [3], e che il lavoro meccanicow e una azione per esso. Inoltre, richiedendo chew verifichi in ogni stato una proprieta di dissipazione, studiamo la classe dei potenziali inferiori perw, cioe l'insieme delle funzioni energia libera.
TL;DR: In this article, the lower semicontinuous envelope and the Γ-limit of degenerate quadratic integral functionals were studied on the space of vector-valued functions of bounded variation defined on an interval.
Abstract: We study the lower semicontinuous envelope and the Γ-limit of degenerate quadratic integral functionals, on the space of the vector-valued functions of bounded variation defined on an interval, which are still quadratic integral functionals. We give an integral representation formula involving a new «relaxed» matrix and some linear contraints on the derivative measure.
TL;DR: In questo lavoro si considerano due tests probabilistici di primalita per interi disparim di forma qualsiasi Gli algoritmi sono tali che sem e dichiarato composto allora lo e certamente, mentre sem and dichiarata primo the risultato ha un certo margine di errore, che puo essere reso arbitrariamente piccolo as mentioned in this paper.
Abstract: In questo lavoro si considerano due tests probabilistici di primalita per interi disparim di forma qualsiasi Gli algoritmi sono tali che sem e dichiarato composto allora lo e certamente, mentre sem e dichiarato primo il risultato ha un certo margine di errore, che puo essere reso arbitrariamente piccolo Un programma scritto e compilato in linguaggio FORTRAN, applicabile ad interi fino a 102000 ed adatto anche a personal computer, permette un confronto dei due tests sulla base del tipo dei risultati e del tempo di elaborazione, fornendo diverse opzioni ed una stima del limite superiore per l’eventuale errore in una dichiarazione di probabile primalita
Abstract: In questo lavoro si determina l'insieme degli zeri di una forma quadratica semidefinita positiva utilizzando l'identita di Picone in uno spazio di Hilbert [6]. Per mezzo di questo risultato vengono poi dedotti alcuni teoremi di confronto di Sturm per equazioni differenziali ellittiche del 2o ordine. Tali teoremi sono «forti», cioe gli «zeri» delle soluzioni sono considerati in Ů anziche inD.