Search results for "variational methods"

showing 10 items of 20 documents

Two non-zero solutions for Sturm–Liouville equations with mixed boundary conditions

2019

Abstract In this paper, we establish the existence of two non-zero solutions for a mixed boundary value problem with the Sturm–Liouville equation. The approach is based on a recent two critical point theorem.

Sturm–Liouville theoryCritical points01 natural sciencesCritical point (mathematics)Critical pointSturm–Liouville equationVariational methodsBoundary value problem0101 mathematicsBoundary value problem; Critical points; Mixed conditions; Sturm–Liouville equation; Variational methodsBoundary value problemMathematicsApplied Mathematics010102 general mathematicsMathematical analysisGeneral EngineeringVariational methodAnalysiGeneral MedicineMathematics::Spectral Theory010101 applied mathematicsComputational MathematicsMixed conditionGeneral Economics Econometrics and FinanceMixed conditionsAnalysis
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Existence, nonexistence and uniqueness of positive solutions for nonlinear eigenvalue problems

2017

We study the existence of positive solutions for perturbations of the classical eigenvalue problem for the Dirichlet $p-$Laplacian. We consider three cases. In the first the perturbation is $(p-1)-$sublinear near $+\infty$, while in the second the perturbation is $(p-1)-$superlinear near $+\infty$ and in the third we do not require asymptotic condition at $+\infty$. Using variational methods together with truncation and comparison techniques, we show that for $\lambda\in (0, \widehat{\lambda}_1)$ -$\lambda>0$ is the parameter and $\widehat{\lambda}_1$ being the principal eigenvalue of $\left(-\Delta_p, W^{1, p}_0(\Omega)\right)$ -we have positive solutions, while for $\lambda\geq \widehat{\…

Sublinear functionMonotonic functionLambda01 natural sciencesOmegaDirichlet distributionsymbols.namesakeFirst eigenvalueP-LaplacianUniqueness0101 mathematicsEigenvalues and eigenvectorsMathematical physicsNonlinear regularityPhysicsApplied Mathematics010102 general mathematicsMathematical analysisVariational methodAnalysiFirst eigenvalue; Generalized picone's identity; Nonlinear maximum principle; Nonlinear regularity; P-Laplacian; Variational methods; Analysis; Applied MathematicsGeneral Medicine010101 applied mathematicsp-LaplaciansymbolsNonlinear maximum principleGeneralized picone's identityAnalysis
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Nonlinear elliptic equations with asymmetric asymptotic behavior at $pminfty$

2016

We consider a nonlinear, nonhomogeneous Dirichlet problem with reaction which is asymptotically superlinear at $+infty$ and sublinear at $-infty$. Using minimax methods together with suitable truncation techniques and Morse theory, we show that the problem has at least three nontrivial solutions one of which is negative.

Variational methodsNonlinear maximum principleResonanceAsymmetric reactionCritical groupNonlinear regularity
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Variational Bethe ansatz approach for dipolar one-dimensional bosons

2020

We propose a variational approximation to the ground state energy of a one-dimensional gas of interacting bosons on the continuum based on the Bethe Ansatz ground state wavefunction of the Lieb-Liniger model. We apply our variational approximation to a gas of dipolar bosons in the single mode approximation and obtain its ground state energy per unit length. This allows for the calculation of the Tomonaga-Luttinger exponent as a function of density and the determination of the structure factor at small momenta. Moreover, in the case of attractive dipolar interaction, an instability is predicted at a critical density, which could be accessed in lanthanide atoms.

[PHYS.COND.GAS]Physics [physics]/Condensed Matter [cond-mat]/Quantum Gases [cond-mat.quant-gas]Dipolar interactionsFOS: Physical sciences02 engineering and technologyGas atomici interagenti01 natural sciencesBethe ansatzVariational methods in quantum mechanicsCondensed Matter - Strongly Correlated ElectronsQuantum mechanics0103 physical sciencesLieb–Liniger model010306 general physicsWave function[PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall]BosonPhysicsCondensed Matter::Quantum GasesLieb-Liniger modelStrongly Correlated Electrons (cond-mat.str-el)one dimensional bosonsFunction (mathematics)021001 nanoscience & nanotechnologyQuantum Gases (cond-mat.quant-gas)Exponent[PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el]0210 nano-technologyStructure factorGround stateCondensed Matter - Quantum Gases
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Existence of three solutions for a mixed boundary value system with (p_1,...,p_m)-Laplacian

2014

In this paper we prove the existence of at least three weak solutions for a mixed boundary value system with (p_1,,...,p_m)-Laplacian. The approach is based on variational methods.

critical points variational methods p-LaplacianSettore MAT/05 - Analisi Matematica
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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.

nonlinear elliptic problemmultiple solutionsVariational methodsp-Laplace operatorSettore MAT/05 - Analisi MatematicaGeneral Mathematicscritical pointRendiconti Lincei - Matematica e Applicazioni
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Two positive solutions for a nonlinear parameter-depending algebraic system

2021

The existence of two positive solutions for a nonlinear parameter-depending algebraic system is investigated. The main tools are a finite dimensional version of a two critical point theorem and a recent weak-strong discrete maximum principle.

positive solutionSettore MAT/05 - Analisi Matematicavariational methodsNonlinear algebraic system
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Two positive solutions for a nonlinear parameter-depending algebraic system

2021

The existence of two positive solutions for a nonlinear parameter-depending algebraic system is investigated. The main tools are a finite dimensional version of a two critical point theorem and a recent weak-strong discrete maximum principle.

positive solutionspositive solutionSettore MAT/05 - Analisi Matematicavariational methodsNonlinear algebraic systemNonlinear algebraic systems; positive solutions; variational methodsNonlinear algebraic systems
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Existence of two solutions for singular Φ-Laplacian problems

2022

AbstractExistence of two solutions to a parametric singular quasi-linear elliptic problem is proved. The equation is driven by theΦ\Phi-Laplacian operator, and the reaction term can be nonmonotone. The main tools employed are the local minimum theorem and the Mountain pass theorem, together with the truncation technique. GlobalC1,τ{C}^{1,\tau }regularity of solutions is also investigated, chiefly viaa prioriestimates and perturbation techniques.

singular termΦ-LaplacianSettore MAT/05 - Analisi MatematicaGeneral MathematicsSobolev-Orlicz spaceFOS: Mathematicsvariational methodsStatistical and Nonlinear Physics35J20 35J25 35J62Analysis of PDEs (math.AP)Advanced Nonlinear Studies
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Multiple solutions for a Sturm-Liouville problem with periodic boundary conditions

2013

The main purpose of this paper is to establish the existence of multiple solutions for a Sturm-Liouville problem with periodic boundary conditions. The approach is based on variational methods and multiple critical points theorems

variational methods periodic boundary conditionsSettore MAT/05 - Analisi Matematica
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