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Finite group with given Hall normally embedded subgroups Ricerche mat. (IF 1.2) Pub Date : 2024-03-06 Xuanli He, Qinhui Sun, Jing Wang
Let G be a finite group. A subgroup H of G is called Hall normally embedded in G if H is a Hall subgroup of the normal closure \(H^G\). In this paper, we fix a subgroup D of Sylow p-subgroup P of G with \(1<|D|<|O_p(G)|\) and study the structure of G under the assumption that all subgroups H of P with order \(|H|=|D|\) are Hall normally embedded in G.
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On special Clifford groups and their characteristic classes Ricerche mat. (IF 1.2) Pub Date : 2024-03-02 Nikita A. Karpenko
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A note on a theorem on conjugacy class sizes Ricerche mat. (IF 1.2) Pub Date : 2024-02-29 Qingjun Kong, Mengjiao Shi
Let \(p\) be a fixed prime, \(a\) and \(n\) are positive integers such that \((p,n) = 1\). It is shown that if \(G\) is a finite group such that for every prime \(q\) the set of the conjugacy class sizes of all \(\{ p,q\} -\) elements of \(G\) is \(\left\{ {1,p^{a} {,}n,p^{a} n} \right\}\), and there is a \(p -\) element in \(G\) whose conjugacy class has size \(p^{a}\), then \(G\) is nilpotent and
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Acceleration waves in a spherical oscillating gas bubble containing a gas mixture Ricerche mat. (IF 1.2) Pub Date : 2024-02-06 Francesca Brini, Leonardo Seccia
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Modelling the impact of opinion flexibility on the vaccination choices during epidemics Ricerche mat. (IF 1.2) Pub Date : 2024-02-03 Rossella Della Marca, Marco Menale
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On recognition of the direct squares of the simple groups with abelian Sylow 2-subgroups Ricerche mat. (IF 1.2) Pub Date : 2024-02-01 Tao Li, Ali Reza Moghaddamfar, Andrey V. Vasil’ev, Zhigang Wang
The spectrum of a group is the set of orders of its elements. Finite groups with the same spectra as the direct squares of the finite simple groups with abelian Sylow 2-subgroups are considered. It is proved that the direct square \(J_1\times J_1\) of the sporadic Janko group \(J_1\) and the direct squares \({^2}G_2(q)\times {^2}G_2(q)\) of the simple small Ree groups \({^2}G_2(q)\) are uniquely characterized
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Two classes of exact solutions in the linear elastodynamics of transversely isotropic solids Ricerche mat. (IF 1.2) Pub Date : 2024-01-13 Kumbakonam R. Rajagopal, Giuseppe Saccomandi, Luigi Vergori
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On the CSS-subgroups and the supersolvabilty of a finite group Ricerche mat. (IF 1.2) Pub Date : 2024-01-11 Xianhe Zhao, Yuxin Zhao, Ruifang Chen, Xiuyun Guo
Recall that a subgroup H of a finite group G is said to be a CSS-subgroup of G if there is a normal subgroup T of G such that \(G=HT\), and \(H\cap T\) is SS-quasinormal in G. Clearly, both the c-normal subgroups and the SS-quasinormal subgroups are the CSS-subgroups, but the converse does not hold. In this paper, based on the research of c-normality and SS-quainormality, with the help of the group
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A characterization of $$(K_n,U^-)$$ in the class L(3) Ricerche mat. (IF 1.2) Pub Date : 2024-01-11 Soudabeh Dalvandi, Farideh Heydari, Mohammad Maghasedi
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Dynamics of neural system under the influence of a magnetic flux Ricerche mat. (IF 1.2) Pub Date : 2024-01-02 Monica De Angelis
An autonomous model describing biological aspects of synapses affected by electromagnetic fields, is considered. A quaternary system comparable to the third-order FitzHuh–Rinzel (FHR) model is obtained. Linear stability criteria and conditions for Hopf bifurcations are achieved also by means of a ternary auxiliary spectrum showing that some of the resulting conditions recall those related to critical
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Regularity for solutions of elliptic $$p(x)-$$ Laplacian type equations with lower order terms and hardy potential Ricerche mat. (IF 1.2) Pub Date : 2023-12-26 Hichem Khelifi, Karima Ait-Mahiout
This paper aims to investigate a type of nonlinear elliptic equation that contains a Hardy potential, lower order term and \(L^{m(.)}\) datum in the setting of Sobolev spaces with variable exponent. Despite the presence of a Hardy potential, the existence of solutions and regularizing effect of some lower order terms in \(p(x)-\)Laplacian type elliptic equations are proved.
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On co-maximal subgroup graph of a group-II Ricerche mat. (IF 1.2) Pub Date : 2023-12-20 Angsuman Das, Manideepa Saha
In this sequel paper, we continue our study on co-maximal subgroup graph \(\Gamma (G)\) of a group G. We discuss some further results on connectedness and when \(\Gamma (G)\) is edgeless. Moreover, we study the independence number, chromatic number and perfectness of \(\Gamma (G)\). In the process, we show that if the independence number is suitably small, then the underlying group is solvable. We
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Finite groups with two kernels of nonlinear irreducible characters Ricerche mat. (IF 1.2) Pub Date : 2023-12-20 Qingyun Meng, Yali Li
In this paper, we consider finite groups with few kernels of nonlinear irreducible characters and classify finite solvable groups with two kernels of nonlinear irreducible characters. Nonsolvable groups with this property are also investigated.
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On the validity of the Fourier law in a Resonant Tunneling Diode Ricerche mat. (IF 1.2) Pub Date : 2023-12-18 Orazio Muscato
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A note on Thompson problem Ricerche mat. (IF 1.2) Pub Date : 2023-12-16 Yu Li, Wujie Shi
In this paper, we prove that if two finite groups G and H have isomorphic Burnside rings, then G and H are the same order type groups, and give an example to show that the Burnside rings of the same order type groups are not necessarily isomorphic. This result is related to the Thompson Problem which was raised in 1987.
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A weak- $$L^{p}$$ Prodi–Serrin type regularity criterion for the micropolar fluid equations in terms of the pressure Ricerche mat. (IF 1.2) Pub Date : 2023-12-15 Ines Ben Omrane, Mourad Ben Slimane, Sadek Gala, Maria Alessandra Ragusa
This paper is devoted to investigating regularity criteria for the 3D micropolar fluid equations in terms of pressure in weak Lebesgue space. More precisely, we mainly proved that the weak solution is regular on (0, T] provided that either the norm \(\left\| \pi \right\| _{L^{\alpha ,\infty }(0,T;L^{\beta ,\infty }(\mathbb {R}^{3}))}\) with \(\frac{2}{\alpha }+ \frac{3}{\beta }=2\) and \(\frac{3}{2}<\beta
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Energy decay of wave equations with infinite memory effects versus supercritical frictional dampings Ricerche mat. (IF 1.2) Pub Date : 2023-12-11 Menglan Liao
In this paper, a class of damped viscoelastic wave equations $$\begin{aligned} u_{tt}-k(0)\Delta u-\int _0^\infty k'(s)\Delta u(t-s)ds+|u_t|^{m-1}u_t=|u|^{p-1}u \end{aligned}$$ is considered in a bounded domain \(\Omega \subset {\mathbb {R}}^3\). Uniform energy decay was discussed which depends on the relaxation function \(-k'(s)\) in the previous work (Guo et al., Z Angew Math Phys 69:65, 2018) for
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A hyperbolic reaction–diffusion model of chronic wasting disease Ricerche mat. (IF 1.2) Pub Date : 2023-12-09 Elvira Barbera, Annamaria Pollino
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Nilpotent groups whose difference graphs have positive genus Ricerche mat. (IF 1.2) Pub Date : 2023-12-02 Parveen, Jitender Kumar
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Existence of solutions for the problem of microwave heating and a Liapunoff criteria for stability and instability Ricerche mat. (IF 1.2) Pub Date : 2023-11-26 Giovanni Cimatti
The Galerkin’s method is applied to prove the existence of at least one solution of the initial boundary value problem for the nonlinear system of partial differential equations modelling the electromagnetic heating of materials. In addition a criteria of stability and instability based on a Liapunoff function is presented.
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Some notes on the algebraic structure of linear recurrent sequences Ricerche mat. (IF 1.2) Pub Date : 2023-11-27 Gessica Alecci, Stefano Barbero, Nadir Murru
Several operations can be defined on the set of all linear recurrent sequences, such as the binomial convolution (Hurwitz product) or the multinomial convolution (Newton product). Using elementary techniques, we prove that this set equipped with the termwise sum and the aforementioned products is an R-algebra, given any commutative ring R with identity. Moreover, we provide explicitly a characteristic
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Hopf bifurcation and Turing patterns for a diffusive predator–prey system with weak Allee effect Ricerche mat. (IF 1.2) Pub Date : 2023-11-03 Wenbin Yang, Xin Chang
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On the dynamics of a Leslie–Gower predator–prey ternary model with intraguild Ricerche mat. (IF 1.2) Pub Date : 2023-11-04 C. Accarino, F. Capone, R. De Luca, G. Massa
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Group identities on symmetric units under oriented involutions in group algebras Ricerche mat. (IF 1.2) Pub Date : 2023-10-25 Alexander Holguín-Villa, John H. Castillo
Let \(\mathbb {F}G\) denote the group algebra of a locally finite group G over the infinite field \(\mathbb {F}\) with \(\mathop {\textrm{char}}\nolimits (\mathbb {F})\ne 2\), and let \(\circledast :\mathbb {F}G\rightarrow \mathbb {F}G\) denote the involution defined by \(\alpha =\Sigma \alpha _{g}g \mapsto \alpha ^\circledast =\Sigma \alpha _{g}\sigma (g)g^{*}\), where \(\sigma :G\rightarrow \{\pm
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Turing instability for a Leslie–Gower model Ricerche mat. (IF 1.2) Pub Date : 2023-10-11 F. Capone, R. De Luca, L. Fiorentino, V. Luongo, G. Massa
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Correction: A chemotaxis reaction–diffusion model for Multiple Sclerosis with Allee effect Ricerche mat. (IF 1.2) Pub Date : 2023-10-10 Marzia Bisi, Maria Groppi, Giorgio Martalò, Cinzia Soresina
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Temporal to spatial instability in a flow system: a comparison Ricerche mat. (IF 1.2) Pub Date : 2023-10-03 Antonio Barletta
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Hydrodynamic regime and cold plasmas hit by short laser pulses Ricerche mat. (IF 1.2) Pub Date : 2023-10-01 Gaetano Fiore, Monica De Angelis, Renato Fedele, Gabriele Guerriero, Dušan Jovanović
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Egyptian integral domains Ricerche mat. (IF 1.2) Pub Date : 2023-09-28 Neil Epstein
The notion of an Egyptian domain (where the analogue of Egyptian fractions works appropriately), first explored by Guerrieri–Loper–Oman, is extended to the more general notions of generically and locally Egyptian domains. Results from the previous paper are extended, as well as reinterpreted in the new expanded context. It is shown that localizations of polynomial rings are typically Egyptian, that
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The impact of the solubilizer of an element on the structure of a finite group Ricerche mat. (IF 1.2) Pub Date : 2023-09-24 Hamid Mousavi, Mina Poozesh, Yousef Zamani
Let G be a finite group, and let x be an element of G. Denote by \({{\,\textrm{Sol}\,}}_G(x)\) the set of all \(y \in G\) such that the group generated by x and y is soluble. We investigate the influence of \({{\,\textrm{Sol}\,}}_G(x)\) on the structure of G.
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Spectral and Energy–Lyapunov stability of streamwise Couette–Poiseuille and spanwise Poiseuille base flows Ricerche mat. (IF 1.2) Pub Date : 2023-09-16 Andrea Giacobbe, Carla Perrone
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Excitable FitzHugh-Nagumo model with cross-diffusion: long-range activation instabilities Ricerche mat. (IF 1.2) Pub Date : 2023-09-12 G. Gambino, M. C. Lombardo, R. Rizzo, M. Sammartino
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Excitable FitzHugh-Nagumo model with cross-diffusion: close and far-from-equilibrium coherent structures Ricerche mat. (IF 1.2) Pub Date : 2023-09-11 G. Gambino, M. C. Lombardo, R. Rizzo, M. Sammartino
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A note on the Caristi fixed point theorem Ricerche mat. (IF 1.2) Pub Date : 2023-09-11 Oleg Zubelevich
We generalize the Caristi fixed point theorem and the contraction mapping principle to the mappings of the complete semi-metric spaces.
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Compound transmuted family of distributions: properties and applications Ricerche mat. (IF 1.2) Pub Date : 2023-08-28 Coşkun Kuş, Kadir Karakaya, Caner Tanış, Yunus Akdoğan, Sümeyra Sert, Fahreddin Kalkan
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Throughflow effect on bi-disperse convection Ricerche mat. (IF 1.2) Pub Date : 2023-08-28 Florinda Capone, Roberta De Luca, Giuliana Massa
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Time-like definition of quaternions in exterior algebra Ricerche mat. (IF 1.2) Pub Date : 2023-08-22 Ivano Colombaro
A formal description of quaternions by means of exterior calculus is presented. Considering a three-dimensional space-time characterized by three time-like coordinates, we have been able to consistently recover a suitable formulation of quaternions by means of the properties arising from exterior algebra and calculus. As an application, it is also illustrated how rotations may be written in terms of
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The Rionero’s special type of Lyapunov function and its application to a diffusive epidemic model with information Ricerche mat. (IF 1.2) Pub Date : 2023-08-22 Bruno Buonomo, Alberto d’Onofrio
We consider a SIR-like reaction-diffusion epidemic model which embeds opinion-driven human behavioural changes. We assume that the contagion rate is theoretically saturated with respect to the density of the disease prevalence. The model extends the general reaction-diffusion epidemic model proposed in 1993 by Capasso and Di Liddo. We study the nonlinear attractivity of the endemic steady state solution
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Modelling domain-wall orientation in antiferromagnets driven by magnetoelastic interactions and volume variations Ricerche mat. (IF 1.2) Pub Date : 2023-08-11 Giancarlo Consolo, Olena V. Gomonay, Pierandrea Vergallo
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New upper bounds for graph energy Ricerche mat. (IF 1.2) Pub Date : 2023-08-05 S. B. Bozkurt Altındağ, I. Milovanović, E. Milovanović
For a graph G of order n, the (ordinary) graph energy, denoted by \( E\left( G\right) ,\) is defined as \(E\left( G\right) =\sum _{i=1}^{n}\left| \lambda _{i}\right| \), where \(\lambda _{1}\ge \lambda _{2}\ge \cdots \ge \lambda _{n}\), are the eigenvalues of G. In this paper, new upper bounds for E(G) are presented. From two of these results, some earlier known upper bounds on E(G) could be improved
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A chemotaxis reaction–diffusion model for Multiple Sclerosis with Allee effect Ricerche mat. (IF 1.2) Pub Date : 2023-08-04 Marzia Bisi, Maria Groppi, Giorgio Martalò, Cinzia Soresina
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About the triangular Shigesada–Kawasaki–Teramoto reaction cross diffusion system Ricerche mat. (IF 1.2) Pub Date : 2023-08-03 L. Desvillettes
We show how the use of a refined version of the duality method together with the use of more traditional multiplicators enables to quickly get regularity results for the so-called “triangular” Shigesada–Kawasaki–Teramoto system. This system is the coupling of a reaction diffusion equation with a reaction cross diffusion equation. It comes out of the study of segregation in biological populations and
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Finite groups with some solvable SNS-groups Ricerche mat. (IF 1.2) Pub Date : 2023-07-31 Wanlin Wang, Pengfei Guo
A finite group G is called an SNS-group if every subgroup of G is either subnormal in G or self-normalizing. In this article, we investigate the structure of finite groups which are not SNS-groups but all of whose maximal subgroups of even order are SNS-groups. In addition, we determine the minimal simple groups all of whose second maximal subgroups (respectively, second maximal subgroups of even order)
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Effects of population dispersals on measles dynamics Ricerche mat. (IF 1.2) Pub Date : 2023-07-29 Kaifa Wang, Wendi Wang
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Quaternion algebra approach to nonlinear Schrödinger equations with nonvanishing boundary conditions Ricerche mat. (IF 1.2) Pub Date : 2023-07-28 Francesco Demontis, Cornelis van der Mee
In this article we apply quaternionic linear algebra and quaternionic linear system theory to develop the inverse scattering transform theory for the nonlinear Schrödinger equation with nonvanishing boundary conditions. We also determine its soliton solutions by using triplets of quaternionic matrices.
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A domain decomposition approach for wave propagation into a layered domain Ricerche mat. (IF 1.2) Pub Date : 2023-07-28 Angela Ricciardello
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First-order thermodynamics of scalar-tensor gravity Ricerche mat. (IF 1.2) Pub Date : 2023-07-26 Serena Giardino, Andrea Giusti
The first-order thermodynamics of scalar-tensor theory is a novel approach that exploits the intriguing relationship between gravity and thermodynamics to better understand the space of gravity theories. It is based on using Eckart’s first-order irreversible thermodynamics on the effective imperfect fluid describing scalar-tensor gravity and characterises General Relativity as an equilibrium state
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Finite p-groups whose non-normal cyclic subgroups have cyclic quotient groups in their normalizers Ricerche mat. (IF 1.2) Pub Date : 2023-07-15 Jiao Wang
A p-group G is called a \(\mathcal {NCC}\)-p-group if \(N_G(\langle x\rangle )/\langle x\rangle \) is cyclic for every non-normal cyclic subgroup \(\langle x\rangle \) in G. In this paper, we give a complete classification of finite \(\mathcal {NCC}\)-p-groups.
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On the distance eigenvalues of design graphs Ricerche mat. (IF 1.2) Pub Date : 2023-07-14 S. Morteza Mirafzal
A design graph is a regular bipartite graph in which any two distinct vertices of the same part have the same number of common neighbors. This class of graphs has a close relationship to strongly regular graphs. In this paper, we study the distance eigenvalues of the design graphs. Also, we will explicitly determine the distance eigenvalues of a class of design graphs, and determine the values for
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Zero relaxation limit in BV Ricerche mat. (IF 1.2) Pub Date : 2023-07-14 Constantine M. Dafermos
The paper considers a family of hyperbolic systems of balance laws, with source manifesting relaxation, encountered in continuum physics. It is parametrized by the relaxation time parameter \(\mu \). A class of initial data is identified for which the Cauchy problem is well-posed, in the BV setting, for all \(\mu >0\), and the zero relaxation limit is determined as \(\mu \rightarrow 0\).
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On some aspects of the Kegel–Wielandt $$\sigma $$ -problem Ricerche mat. (IF 1.2) Pub Date : 2023-07-10 Zh. Xu, X. Yi, S. F. Kamornikov
Let \(\sigma = \{\sigma _i | i \in I \}\) be a partition of the set of all primes. A subgroup H of a finite group G is called \(\sigma \)-subnormal in G if there exists a chain of subgroups $$\begin{aligned} H = H_0 \subseteq H_1 \subseteq \cdots \subseteq H_n = G \end{aligned}$$ such that for every \(j = 1, 2,\ldots , n\) either \(H_{j-1}\) is normal in \(H_j\) or \(H_j / Core_{H_j}(H_{j-1})\) is
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A note on weakly $$\sigma $$ -n-embedded subgroups of $$\sigma $$ -full groups Ricerche mat. (IF 1.2) Pub Date : 2023-07-11 Muhammad Tanveer Hussain, Zain Ul Abadin Zafar, Shamsher Ullah
Let \(\sigma =\{\sigma _i: i\in I\}\) be a partition of the set \({\mathbb {P}}\) of all prime numbers. A subgroup H of a finite group G is called \(\sigma \)-subnormal in G if there is a chain of subgroups \(H = H_0 \subseteq H_1 \subseteq \cdots \subseteq H_n = G\) where, for every \(i =1,\ldots , n\), \(H_{i-1}\) normal in \(H_i\) or \(H_i/(H_{i-1})_{H_i}\) is a \(\sigma _i\)-group for some \(i\in
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Double wave solutions for a hyperbolic model describing nerve fiber Ricerche mat. (IF 1.2) Pub Date : 2023-07-11 Natale Manganaro, Alessandra Rizzo
In this article, within the framework of the method of differential constraints, we develop a reduction procedure aimed at determining exact solutions to a first order hyperbolic system which describes nerve pulse propagation. In fact, we look for particular double wave solutions and we reduce the integration of the full system to that of a suitable \(2 \times 2\) sub-system. The solutions we obtain
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Monotone energy stability of magnetohydrodynamics Couette and Hartmann flows Ricerche mat. (IF 1.2) Pub Date : 2023-07-06 Giuseppe Mulone
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Competitive porous double diffusion with Korteweg stress Ricerche mat. (IF 1.2) Pub Date : 2023-07-07 Brian Straughan
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One-dimensional Barenblatt-type solutions and related inequalities Ricerche mat. (IF 1.2) Pub Date : 2023-07-06 Giuseppe Toscani
We present and discuss connections between the problem of trend to equilibrium for one-dimensional Fokker–Planck equations, and one-dimensional functional inequalities of the type of Poincaré and Wirtinger, with weight, for probability densities in the form of one-dimensional Barenblatt solutions of the porous medium equation. It it also shown that Hardy’s classical one-dimensional inequality can be
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Nonlinear stability analysis of a chemical reaction–diffusion system Ricerche mat. (IF 1.2) Pub Date : 2023-07-06 Maurizio Gentile, Isabella Torcicollo
A reaction–diffusion model, known as the Sel’kov–Schnakenberg model, is considered. The nonlinear stability of the constant steady state is studied by using a special Liapunov functional and a maximum principle for regular solutions.
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Turing vegetation patterns in flat arid environments with finite soil carrying capacity Ricerche mat. (IF 1.2) Pub Date : 2023-07-03 Giancarlo Consolo, Gabriele Grifó
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Principle of virtual action in continuum mechanics Ricerche mat. (IF 1.2) Pub Date : 2023-07-03 Henri Gouin
We present the principle of virtual action as a foundation of continuum mechanics. Used mainly in relativity, the method has a useful application in classical mechanics and places the notion of action as the basic concept of dynamics. The principle is an extension of virtual work to space-time. It extends the efforts made by d’Alembert and Lagrange. Unlike the classical case of equilibrium, the principle