Search results for "solution"

showing 10 items of 5638 documents

Projective resolutions associated to projections

2000

In this paper we will describe projective resolutions of d dimensional Cohen–Macaulay spaces X by means of a projection of X to a hypersurface in d+1-dimensional space. We will show that for a certain class of projections, the resulting resolution is minimal.

Pure mathematicsHypersurfaceNumber theoryMathematics::Commutative AlgebraProjection (mathematics)General MathematicsProjective spaceAlgebraic geometryProjective testSpace (mathematics)MathematicsResolution (algebra)manuscripta mathematica
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On the interior regularity of weak solutions to the 2-D incompressible Euler equations

2016

We study whether some of the non-physical properties observed for weak solutions of the incompressible Euler equations can be ruled out by studying the vorticity formulation. Our main contribution is in developing an interior regularity method in the spirit of De Giorgi–Nash–Moser, showing that local weak solutions are exponentially integrable, uniformly in time, under minimal integrability conditions. This is a Serrin-type interior regularity result $$\begin{aligned} u \in L_\mathrm{loc}^{2+\varepsilon }(\Omega _T) \implies \mathrm{local\ regularity} \end{aligned}$$ for weak solutions in the energy space $$L_t^\infty L_x^2$$ , satisfying appropriate vorticity estimates. We also obtain impr…

Pure mathematicsIntegrable systemDimension (graph theory)Mathematics::Analysis of PDEsContext (language use)yhtälötSpace (mathematics)01 natural sciencessymbols.namesakeMathematics - Analysis of PDEs35Q31 (Primary) 76B03 35B65 35Q30 (Secondary)weak solutions0103 physical sciencesinterior regularityBoundary value problem0101 mathematicsMathematicsmatematiikkaApplied Mathematics010102 general mathematicsVorticityEuler equationsEuler equationssymbols010307 mathematical physicsAnalysisEnergy (signal processing)Calculus of Variations and Partial Differential Equations
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Nonlinear balayage on metric spaces

2009

We develop a theory of balayage on complete doubling metric measure spaces supporting a Poincaré inequality. In particular, we are interested in continuity and p-harmonicity of the balayage. We also study connections to the obstacle problem. As applications, we characterize regular boundary points and polar sets in terms of balayage. Original Publication:Anders Björn, Jana Björn, Tero Mäkäläinen and Mikko Parviainen, Nonlinear balayage on metric spaces, 2009, Nonlinear Analysis, (71), 5-6, 2153-2171.http://dx.doi.org/10.1016/j.na.2009.01.051Copyright: Elsevier Science B.V., Amsterdam.http://www.elsevier.com/

Pure mathematicsMatematikBalayageApplied MathematicsMathematical analysisPoincaré inequalityBoundary (topology)Measure (mathematics)symbols.namesakeMetric spaceMetric (mathematics)Obstacle problemsymbolsBalayage; Boundary regularity; Continuity; Doubling measure; Metric space; Nonlinear; Obstacle problem; Perron solution; p-harmonic; Polar set; Poincaré inequality; Potential theory; SuperharmonicAnalysisMathematicsMathematicsPolar set (potential theory)
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Nonlinear scalar field equations with general nonlinearity

2018

Consider the nonlinear scalar field equation \begin{equation} \label{a1} -\Delta{u}= f(u)\quad\text{in}~\mathbb{R}^N,\qquad u\in H^1(\mathbb{R}^N), \end{equation} where $N\geq3$ and $f$ satisfies the general Berestycki-Lions conditions. We are interested in the existence of positive ground states, of nonradial solutions and in the multiplicity of radial and nonradial solutions. Very recently Mederski [30] made a major advance in that direction through the development, in an abstract setting, of a new critical point theory for constrained functionals. In this paper we propose an alternative, more elementary approach, which permits to recover Mederski's results on the scalar field equation. T…

Pure mathematicsMathematics::Analysis of PDEsMonotonic function2010 MSC: 35J20 35J6001 natural sciencesMathematics - Analysis of PDEsFOS: Mathematics[MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP]Mountain pass0101 mathematicsMathematicsgeographygeography.geographical_feature_category35J20 35J60Applied Mathematics010102 general mathematicsMultiplicity (mathematics)Monotonicity trickNonradial solutions010101 applied mathematicsNonlinear systemBerestycki-Lions nonlinearityBounded functionNonlinear scalar field equationsScalar fieldAnalysisAnalysis of PDEs (math.AP)
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Continuous numerical solutions of coupled mixed partial differential systems using Fer's factorization

1999

In this paper continuous numerical solutions expressed in terms of matrix exponentials are constructed to approximate time-dependent systems of the type ut A(t)uxx B(t)u=0; 0 0, u(0;t)=u(p;t)=0; u(x;0)=f(x);06 x6p. After truncation of an exact series solution, the numerical solution is constructed using Fer’s factorization. Given >0 and t0;t1; with 0<t0<t1 and D(t0;t1)=f(x;t); 06x6p; t06t6t1g the error of the approximated solution with respect to the exact series solution is less than uniformly in D(t0;t1). An algorithm is also included. c 1999 Elsevier Science B.V. All rights reserved. AMS classication: 65M15, 34A50, 35C10, 35A50

Pure mathematicsPartial differential equationSeries (mathematics)TruncationApplied MathematicsMixed time-dependent partial differential systemsType (model theory)Fer's factorizationExponential functionAlgorithmCombinatoricsComputational MathematicsMatrix (mathematics)Accurate solutionFactorizationPartial derivativeA priori error boundsMathematicsJournal of Computational and Applied Mathematics
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Nonexistence of global weak solutions for a nonlinear Schrodinger equation in an exterior domain

2020

We study the large-time behavior of solutions to the nonlinear exterior problem L u ( t , x ) = &kappa

Pure mathematicsPhysics and Astronomy (miscellaneous)General MathematicsGlobal weak solution01 natural sciencesDomain (mathematical analysis)symbols.namesakeSettore MAT/05 - Analisi MatematicaComputer Science (miscellaneous)Neumann boundary conditionNonlinear Schrödinger equationBall (mathematics)0101 mathematicsNonlinear Schrödinger equationPhysicsComplex-valued functionOpen unitOperator (physics)lcsh:Mathematics010102 general mathematicsUnit normal vectorlcsh:QA1-939010101 applied mathematicsMathematics::LogicChemistry (miscellaneous)symbolsExterior domainNonhomegeneous Neumann boundary condition
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Fixed Points for Multivalued Weighted Mean Contractions in a Symmetric Generalized Metric Space

2020

This paper defines two new concepts: the concept of multivalued left-weighted mean contractions in the generalized sense of Nadler in a symmetric generalized metric space and the concept of multivalued right-weighted mean contractions in the generalized sense of Nadler in a symmetric generalized metric space, and demonstrates fixed-point theorems for them. For these, we demonstrated two fixed-point existence theorems and their corollaries, by using the properties of the regular-global-inf function and the properties of symmetric generalized metric spaces, respectively. Moreover, we demonstrated that the theorems can be applied in particular cases of inclusion systems. This article contains …

Pure mathematicsPhysics and Astronomy (miscellaneous)multivalued left-weighted mean contractionGeneral Mathematicslcsh:Mathematicsfixed points010102 general mathematicsFunction (mathematics)Fixed pointlcsh:QA1-93901 natural sciences010101 applied mathematicsMetric spaceChemistry (miscellaneous)Computer Science (miscellaneous)In real lifeOrder (group theory)0101 mathematicsEquilibrium solutionWeighted arithmetic meanmultivalued right-weighted mean contractionregular-global-inf functionMathematicsSymmetry
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Positive solutions for the Neumann p-Laplacian

2017

We examine parametric nonlinear Neumann problems driven by the p-Laplacian with asymptotically ( $$p-1$$ )-linear reaction term f(z, x) (as $$x\rightarrow +\infty $$ ). We determine the existence, nonexistence and minimality of positive solutions as the parameter $$\lambda >0$$ varies.

Pure mathematicsPositive solutions Nonlinear regularity Nonlinear maximum principle Nonlinear Picone’s identityGeneral Mathematics010102 general mathematicsMathematical analysisLambda01 natural sciencesTerm (time)010101 applied mathematicsNonlinear systemSettore MAT/05 - Analisi Matematicap-Laplacian0101 mathematicsParametric statisticsMathematics
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A construction of equivariant bundles on the space of symmetric forms

2021

We construct stable vector bundles on the space of symmetric forms of degree d in n+1 variables which are equivariant for the action of SL_{n+1}(C), and admit an equivariant free resolution of length 2. For n=1, we obtain new examples of stable vector bundles of rank d-1 on P^d, which are moreover equivariant for SL_2(C). The presentation matrix of these bundles attains Westwick's upper bound for the dimension of vector spaces of matrices of constant rank and fixed size.

Pure mathematicsRank (linear algebra)General MathematicsVector bundlestable vector bundlesSpace (mathematics)Mathematics - Algebraic GeometryMatrix (mathematics)symmetric formsDimension (vector space)FOS: MathematicsRepresentation Theory (math.RT)Algebraic Geometry (math.AG)Mathematics::Symplectic Geometryhomogeneous varietyMathematicsequivariant resolution14J60quiver representationconstant rank matrixhomogeneous bundleEquivariant mapgroup actionStable vector bundles; symmetric forms; group action; equivariant resolution; constant rank matrix; homogeneous bundle; homogeneous variety; quiver representationMathematics - Representation TheoryResolution (algebra)Vector spaceRevista Matemática Iberoamericana
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Perturbed eigenvalue problems for the Robin p-Laplacian plus an indefinite potential

2020

AbstractWe consider a parametric nonlinear Robin problem driven by the negativep-Laplacian plus an indefinite potential. The equation can be thought as a perturbation of the usual eigenvalue problem. We consider the case where the perturbation$$f(z,\cdot )$$f(z,·)is$$(p-1)$$(p-1)-sublinear and then the case where it is$$(p-1)$$(p-1)-superlinear but without satisfying the Ambrosetti–Rabinowitz condition. We establish existence and uniqueness or multiplicity of positive solutions for certain admissible range for the parameter$$\lambda \in {\mathbb {R}}$$λ∈Rwhich we specify exactly in terms of principal eigenvalue of the differential operator.

Pure mathematicsSublinear functionPerturbation (astronomy)Sublinear and superlinear perturbationLambda01 natural sciencesNonlinear Picone’s identitySettore MAT/05 - Analisi MatematicaUniqueness0101 mathematicsMathematical PhysicsEigenvalues and eigenvectorsPositive solutionsMathematicsNonlinear regularityAlgebra and Number TheoryMinimal positive solution010102 general mathematicsDifferential operator010101 applied mathematicsNonlinear systemp-LaplacianIndefinite potentialUniquenessNonlinear maximum principleAnalysis
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