Ricerche di Matematica

Items from 1 to 20 out of 21 results

article

Extended generalized $$(Zakh\frac{G^{\prime }}{G})$$ ( Z a k h G ′ G ) -expansion method for solving the nonlinear quantum Zakharov–Kuznetsov equation

E. M. E. Zayed, K. A. E. Alurrfi

Ricerche di Matematica > 2016 > 65 > 1 > 235-254

In this article, we apply the extended generalized $$(\frac{G^{\prime }}{G})$$ ( G ′ G ) -expansion method combined with the Jacobi elliptic equation to find new exact solutions of the nonlinear quantum Zakharov–Kuznetsov (QZK) equation with the aid of computer algebraic system Maple. Soliton solutions, periodic solutions, rational functions solutions and Jacobi elliptic functions solutions...

article

Infinitely many solutions for a nonlinear difference equation with oscillatory nonlinearity

Maria Mălin, Vicenţiu D. Rădulescu

Ricerche di Matematica > 2016 > 65 > 1 > 193-208

In this paper, we study a discrete nonlinear boundary value problem that involves a nonlinear term oscillating near the origin and a power-type nonlinearity $$u^p$$ u p . By using variational methods, we establish the existence of a sequence of non-negative weak solutions that converges to 0 if $$p\ge 1$$ p ≥ 1 . In the sublinear case, we prove that for all n positive integer,...

article

CLR-type inequality on a suitable smooth manifold

Mohammed El Aïdi

Ricerche di Matematica > 2016 > 65 > 1 > 155-161

For a real potential belonging to a proper subspace of the set of integrable functions, we provide a new upper bound of the number of negative eigenvalues of a Schrödinger operator defined in a suitable Riemannian manifold.

article

Porous MHD convection: stabilizing effect of magnetic field and bifurcation analysis

Florinda Capone, Salvatore Rionero

Ricerche di Matematica > 2016 > 65 > 1 > 163-186

MHD convection in a horizontal porous-layer filled by a plasma, imbedded in a transverse magnetic field and heated from below, is investigated. The critical Rayleigh number is found and, in simple algebraic closed forms, conditions necessary and sufficient for the onset of steady and oscillatory convection are obtained. It is shown that the stabilizing effect of the magnetic field grows with $$Q^2$$...

article

On the SS-quasinormality of the maximal subgroups of a Sylow subgroup in its normalizer

Guo Zhong, Shi-Xun Lin

Ricerche di Matematica > 2016 > 65 > 1 > 187-192

Let H be a subgroup of a finite group G. We say that H is SS-quasinormal in G if H possesses a supplement B such that H permutes with every Sylow subgroup of B. In this paper, we establish the p-nilpotency and supersolvability of a group under the assumption that maximal subgroups of a Sylow subgroup are SS-quasinormal in the G-normalizer of the Sylow subgroup.

article

Groups satisfying the double chain condition on subnormal subgroups

Mattia Brescia, Francesco Giovanni

Ricerche di Matematica > 2016 > 65 > 1 > 255-261

If $$\theta $$ θ is a subgroup property, a group G is said to satisfy the double chain condition on $$\theta $$ θ -subgroups if it admits no infinite double sequences $$\begin{aligned} \cdots <X_{-n}<\cdots <X_{-1}<X_0<X_1<\cdots <X_n<\cdots \end{aligned}$$ ⋯ < X - n < ⋯ < X - 1 < X 0 < X 1 < ⋯ < X n < ⋯ ...

article

Weighted fully measurable grand Lebesgue spaces and the maximal theorem

Giuseppina Anatriello, Maria Rosaria Formica

Ricerche di Matematica > 2016 > 65 > 1 > 221-233

Anatriello and Fiorenza (J Math Anal Appl 422:783–797, 2015) introduced the fully measurable grand Lebesgue spaces on the interval $$(0,1)\subset \mathbb R$$ ( 0 , 1 ) ⊂ R , which contain some known Banach spaces of functions, among which there are the classical and the grand Lebesgue spaces, and the $$EXP_\alpha $$ E X P α spaces $$(\alpha >0)$$ ( α > 0 ) ....

article

Recent results on nonlinear extended thermodynamics of real gases with six fields Part I: general theory

Takashi Arima, Tommaso Ruggeri, Masaru Sugiyama, Shigeru Taniguchi

Ricerche di Matematica > 2016 > 65 > 1 > 263-277

We review the recently developed theory of extended thermodynamics (ET) of real gases with six independent fields, i.e., the mass density, the velocity, the temperature and the dynamic pressure, without adopting near-equilibrium approximation. We discuss the polytropic and non-polytropic cases of rarefied polyatomic gases in detail, including the closure via nonlinear molecular ET.

article

Recent results on nonlinear extended thermodynamics of real gases with six fields Part II: shock wave structure

Shigeru Taniguchi, Takashi Arima, Tommaso Ruggeri, Masaru Sugiyama

Ricerche di Matematica > 2016 > 65 > 1 > 279-288

On the basis of the nonlinear extended thermodynamics theory discussed in Part I, the shock wave structure in a rarefied non-polytropic gas is analyzed. It is found that the effect of nonlinearity in the constitutive equation on the shock wave structure becomes significant only when the Mach number is large. The deviation from the exponential decay in the relaxation profile of the mass density for...

article

Approximation method for solving fixed point problem of Bregman strongly nonexpansive mappings in reflexive Banach spaces

P. Senakka, P. Cholamjiak

Ricerche di Matematica > 2016 > 65 > 1 > 209-220

In this paper, we introduce a new iteration process for solving fixed point problem of Bregman strongly nonexpansive mappings, and then we study a strong convergence theorem for a common fixed point of Bregman strongly nonexpansive mappings in the framework of reflexive Banach spaces.

article

The fractional Fisher information and the central limit theorem for stable laws

Giuseppe Toscani

Ricerche di Matematica > 2016 > 65 > 1 > 71-91

A new information-theoretic approach to the central limit theorem for stable laws is presented. The main novelty is the concept of relative fractional Fisher information, which shares most of the properties of the classical one, included Blachman-Stam type inequalities. These inequalities relate the fractional Fisher information of the sum of n independent random variables to the information contained...

article

Nonlinear parabolic inequalities in Lebesgue-Sobolev spaces with variable exponent

J. Bennouna, B. El Hamdaoui, M. Mekkour, H. Redwane

Ricerche di Matematica > 2016 > 65 > 1 > 93-125

We give an existence result of the obstacle parabolic problem: $$\begin{aligned} \left\{ \begin{array}{ll} u\ge \psi &{}\ \ \text{ a.e. } \text{ in } \ \Omega \times (0,T)\\ \displaystyle \frac{\partial b(x,u)}{\partial t} -div(a(x,t,u,\nabla u))+div(\phi (x,t,u)) =f &{}\ \ \text{ in }\ \Omega \times (0,T) .\\ \end{array} \right. \end{aligned}$$ u ≥ ψ a.e. in Ω...

article

Strongly divided domains

Ahmed Ayache, David E. Dobbs

Ricerche di Matematica > 2016 > 65 > 1 > 127-154

A quasi-local (commutative integral) domain (R, m) is said to be strongly divided if, whenever T is an overring of R (inside its quotient field) and $$P \in $$ P ∈ Spec(T) with $$P\cap R\ne m$$ P ∩ R ≠ m , then $$P \in $$ P ∈ Spec(R). The class of strongly divided domains fits properly between the class of divided domains and the class of pseudo-valuation domains (PVDs)...

article

Sets of type (q, n) in PG(3, q)

Nicola Durante, Vito Napolitano, Domenico Olanda

Ricerche di Matematica > 2016 > 65 > 1 > 65-70

In this paper a description for sets in $${\mathrm {PG}}(3, q)$$ PG ( 3 , q ) of type (q, n) with respect to planes is given.

article

Solving Volterra’s population growth model of arbitrary order using the generalized fractional order of the Chebyshev functions

Kourosh Parand, Mehdi Delkhosh

Ricerche di Matematica > 2016 > 65 > 1 > 307-328

Volterra’s model for population growth in a closed system includes an integral term to indicate accumulated toxicity in addition to the usual terms of the logistic equation, that occurs in ecology. In this paper, a new numerical approximation is introduced for solving this model of arbitrary (integer or fractional) order. The proposed numerical approach is based on the generalized fractional order...

article

Kernel estimates for Schrödinger type operators with unbounded coefficients and critical exponents

Tiziana Durante, Rosanna Manzo, Cristian Tacelli

Ricerche di Matematica > 2016 > 65 > 1 > 289-305

We consider the Schrödinger type operator $$(1+|x|^\alpha )\Delta +c|x|^{\alpha -2}$$ ( 1 + | x | α ) Δ + c | x | α - 2 , for $$\alpha > 2$$ α > 2 , $$c<0$$ c < 0 and $$N>2$$ N > 2 . Heat kernel estimates of the associated semigroup are obtained using the equivalence between weighted Nash inequalities and “weighted” ultracontractivity...

article

Modelling multiple relapses in drug epidemics

J. Mushanyu, F. Nyabadza, G. Muchatibaya, A. G. R. Stewart

Ricerche di Matematica > 2016 > 65 > 1 > 37-63

Drug dependence is a ‘chronic disease’ treatable through rehabilitation. Many drug addicts progress through a series of rehabilitation and relapsing episodes. In this paper, we formulate a mathematical model with n-alternate stages of rehabilitation and relapsing. The dynamics of drug abuse are treated as an infectious disease that spreads through a population. The model analysis shows that the model...

article

Zero-divisors and zero-divisor graphs of power series rings

Amor Haouaoui, Ali Benhissi

Ricerche di Matematica > 2016 > 65 > 1 > 1-13

Let R be a commutative ring with identity, Z(R) its set of zero-divisors and N(R) its nilradical. The zero-divisor graph of R denoted by $$\varGamma (R)$$ Γ ( R ) , is the graph with vertices $$Z(R){\setminus }{(0)}$$ Z ( R ) \ ( 0 ) , with distinct vertices x and y adjacent if and only if $$xy = 0$$ x y = 0 . In this paper we give some results about a zero-divisors...

article

On groups satisfying a symmetric Engel word

M. Farrokhi D. G., Mohammad Reza R. Moghaddam

Ricerche di Matematica > 2016 > 65 > 1 > 15-20

We show that a finite group satisfying the law $$[y,_nx]=[x,_ny]$$ [ y , n x ] = [ x , n y ] ( $$n>1$$ n > 1 ) is nilpotent and utilizing the results of Macdonalds on the structure of groups satisfying the law $$[y,x]=[x,y]$$ [ y , x ] = [ x , y ] , we investigate groups satisfying both of the laws $$[y,x]=[x,y]$$ [ y , x ] = [ x , y ] and ...

article

Cofiniteness and Artinianness of certain local cohomology modules

M. Aghapournahr, Kh. Ahmadi-amoli, M. Y. Sadeghi

Ricerche di Matematica > 2016 > 65 > 1 > 21-36

Let R be a commutative Noetherian ring, I, J be two ideals of R, M be an R-module and $${\mathcal {S}}$$ S be a Serre class of R-modules. A positive answer to the Huneke’s conjecture is given for a Noetherian ring R and minimax R-module M of Krull dimension less than 3, with respect to $${\mathcal {S}}$$ S . There are some results on cofiniteness and Artinianness of local cohomology...

Year:
2016

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65 (21)

Keywords

EXTENDED THERMODYNAMICS (2)
NON-POLYTROPIC GAS (2)
RAREFIED POLYATOMIC GAS (2)
P-NILPOTENT GROUPS (1)
SS-QUASINORMAL SUBGROUPS (1)
ASSOCIATED PRIMES (1)
BANACH FUNCTION SPACES (1)
BASS NUMBERS (1)
BIFURCATION ANALYSIS (1)
BREGMAN STRONGLY NONEXPANSIVE MAPPING (1)
CENTRAL LIMIT THEOREM (1)
CLR-TYPE INEQUALITY (1)
COFINITE MODULES (1)
COLLOCATION METHOD (1)
COMMON FIXED POINT (1)
DIFFERENCE EQUATIONS (1)
DISCRETE LAPLACIAN (1)
DIVIDED DOMAIN (1)
DOUBLE CHAIN CONDITION (1)
DRUG ABUSE (1)
ELLIPTIC OPERATORS (1)
EMBEDDED THEOREM (1)
ENGEL GROUP (1)
ENGEL WORD (1)
ENTROPY SOLUTIONS (1)
EXACT SOLUTIONS (1)
EXTENDED GENERALIZED $$(\FRAC{ G^{\PRIME }}{G})$$ ( G ′ G ) -EXPANSION (1)
FISHER INFORMATION (1)
FRACTIONAL CALCULUS (1)
FRACTIONAL ORDER OF THE CHEBYSHEV FUNCTIONS (1)
GOING-DOWN (1)
GRAPH (1)
HARDY–LITTLEWOOD MAXIMAL OPERATOR (1)
INFORMATION INEQUALITIES (1)
INTEGRAL DOMAIN (1)
INTEGRALITY (1)
INTEGRO-DIFFERENTIAL EQUATION (1)
JACOBI ELLIPTIC FUNCTIONS (1)
KERNEL ESTIMATES (1)
LEAST SQUARES CURVE FITTING (1)
LINEARIZATION PRINCIPLE (1)
LOCAL COHOMOLOGY (1)
MAGNETIC CONVECTION (1)
MALARIA (1)
MATHEMATICAL ECOLOGY (1)
MATHEMATICAL MODEL (1)
MAXIMAL SUBGROUPS (1)
MINIMAX MODULES (1)
MOMENTS THEORY (1)
MOSQUITO BITING (1)
MUCKENHOUPT WEIGHTS (1)
NEGATIVE EIGENVALUES (1)
NILPOTENT GROUP (1)
NONLINEAR QUANTUM ZAKHAROV–KUZNETSOV (QZK) EQUATION (1)
OSCILLATORY NONLINEARITIES (1)
OVERRING (1)
PARABOLIC PROBLEM (1)
PENALIZED EQUATIONS (1)
POROUS MEDIA (1)
POWER SERIES RINGS (1)
PRIME IDEAL (1)
PROJECTIVE SPACES (1)
PSEUDO-VALUATION DOMAIN (1)
PULLBACK (1)
REDUCTIVE PERTURBATION TECHNIQUE (1)
REHABILITATION (1)
RELAPSE (1)
REPRODUCTION NUMBER (1)
SATURATED FORMATION (1)
SERIES OF TRANSFORMATIONS (1)
SERRE SUBCATEGORY (1)
SHOCK WAVE STRUCTURE (1)
SMOOTH MANIFOLD (1)
SOBOLEV SPACE (1)
STABLE LAWS (1)
STEADY AND OSCILLATORY CONVECTION (1)
STRONGLY CONVERGENCE (1)
SUBNORMAL SUBGROUP (1)
SUPERSOLVABLE GROUPS (1)
SYMMETRY (1)
TREED DOMAIN (1)
TWO-CHARACTER SETS (1)
UNBOUNDED COEFFICIENTS (1)
UNIFORMLY FRÈCHET DIFFERENTIABLE (1)
VARIABLE EXPONENT (1)
VARIATIONAL METHODS (1)
VOLTERRA’S POPULATION MODEL (1)
WEIGHTED FULLY MEASURABLE GRAND LEBESGUE SPACES (1)
ZD-MODULES (1)
ZERO-DIVISOR (1)
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Ricerche di Matematica

Extended generalized $$(Zakh\frac{G^{\prime }}{G})$$ ( Z a k h G ′ G ) -expansion method for solving the nonlinear quantum Zakharov–Kuznetsov equation

Infinitely many solutions for a nonlinear difference equation with oscillatory nonlinearity

CLR-type inequality on a suitable smooth manifold

Porous MHD convection: stabilizing effect of magnetic field and bifurcation analysis

On the SS-quasinormality of the maximal subgroups of a Sylow subgroup in its normalizer

Groups satisfying the double chain condition on subnormal subgroups

Weighted fully measurable grand Lebesgue spaces and the maximal theorem

Recent results on nonlinear extended thermodynamics of real gases with six fields Part I: general theory

Recent results on nonlinear extended thermodynamics of real gases with six fields Part II: shock wave structure

Approximation method for solving fixed point problem of Bregman strongly nonexpansive mappings in reflexive Banach spaces

The fractional Fisher information and the central limit theorem for stable laws

Nonlinear parabolic inequalities in Lebesgue-Sobolev spaces with variable exponent

Strongly divided domains

Sets of type (q, n) in PG(3, q)

Solving Volterra’s population growth model of arbitrary order using the generalized fractional order of the Chebyshev functions

Kernel estimates for Schrödinger type operators with unbounded coefficients and critical exponents

Modelling multiple relapses in drug epidemics

Zero-divisors and zero-divisor graphs of power series rings

On groups satisfying a symmetric Engel word

Cofiniteness and Artinianness of certain local cohomology modules

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