Search results for "Equations"

showing 10 items of 955 documents

Inertial modes in stratified rotating neutron stars : An evolutionary description

2005

With (non-barotropic) equations of state valid even when the neutron, proton and electron content of neutron star cores is not in beta equilibrium, we study inertial and composition gravity modes of relativistic rotating neutron stars. We solve the relativistic Euler equations in the time domain with a three dimensional numerical code based on spectral methods, in the slow rotation, relativistic Cowling and anelastic approximations. Principally, after a short description of the gravity modes due to smooth composition gradients, we focus our analysis on the question of how the inertial modes are affected by non-barotropicity of the nuclear matter. In our study, the deviation with respect to …

Nuclear and High Energy PhysicsInertial frame of referenceFOS: Physical sciencesGeneral Relativity and Quantum Cosmology (gr-qc)Astrophysics7. Clean energy01 natural sciencesGeneral Relativity and Quantum CosmologyGravitation[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]symbols.namesake0103 physical sciencesNeutron010303 astronomy & astrophysicsPhysics[PHYS.GRQC] Physics [physics]/General Relativity and Quantum Cosmology [gr-qc]010308 nuclear & particles physicsAstrophysics (astro-ph)Nuclear matterRelativistic Euler equationsComputational physicsEuler equationsNumerical relativityNeutron starClassical mechanics[PHYS.ASTR.CO] Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]symbols[PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc]
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The Hunt for New Physics at the Large Hadron Collider

2010

233 páginas.-- AHEP Group: et al..-- El Pdf del artículo es la versión pre-print: arXiv.1001.2693v1.-- Trabajo presentado al "The International Workshop on Beyond the Standard Model Physics and LHC Signatures (BSM-LHC) celebrado en Boston (USA) del 2 al 4 de junio de 2009.

Nuclear and High Energy PhysicsParticle physicsCold dark matterPhysics::Instrumentation and DetectorsPhysics beyond the Standard ModelFOS: Physical sciencesRANDALL-SUNDRUM MODEL01 natural sciencesHigh Energy Physics - Phenomenology (hep-ph)R-PARITY BREAKING0103 physical sciencesHigh Energy PhysicsANOMALOUS MAGNETIC-MOMENT010306 general physicsParticle Physics - PhenomenologyPhysicsEXPLICIT CP VIOLATIONDARK-MATTER DETECTIONLarge Hadron Collider010308 nuclear & particles physicsPhysicsElectroweak interactionHigh Energy Physics::PhenomenologyFísicaRENORMALIZATION-GROUP EQUATIONSHierarchy problemSupersymmetryAtomic and Molecular Physics and OpticsGRAND UNIFIED THEORIESSUPERSYMMETRIC STANDARD MODELHidden sectorExtra dimensionsHigh Energy Physics - PhenomenologyMINIMAL FLAVOR VIOLATION[PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph]PhenomenologyHigh Energy Physics::ExperimentHIGGS-BOSON PRODUCTION
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Three-body hadron systems with strangeness

2013

Recently, many efforts are being put in studying three-hadron systems made of mesons and baryons and interesting results are being found. In this talk, we summarize the main features of the formalism used to study such three hadron systems with strangeness S = -1, 0 within a framework built on the basis of unitary chiral theories and solution of the Faddeev equations. In particular, we present the results obtained for the pi(K) over barN, K (K) over barN and KK (K) over bar systems and their respective coupled channels. In the first case, we find four Sigma's and two A's with spin-parity J(P) = 1/2(+), in the 1500-1800 MeV region, as two meson-one baryon s-wave resonances. In the second cas…

Nuclear and High Energy PhysicsParticle physicsFaddeev equationsMesonNuclear TheoryHadronNuclear TheoryFOS: Physical sciencesStrangenessFew-body systems01 natural sciencesNuclear physicsNuclear Theory (nucl-th)Few-body systemsHadron spectroscopy0103 physical sciences010306 general physicsNuclear ExperimentPhysicsUnitarity010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyFísicaUnitary chiral theoriesBaryonHigh Energy Physics::Experiment
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Pion-photon transition distribution amplitudes in the Nambu-Jona-Lasinio model

2007

12 pages, 6 figures.-- PACS nrs.: 13.60.-r; 11.10.St; 12.38.Lg; 24.10.Jv.-- ISI Article Identifier: 000251327200049.-- ArXiv pre-print available at: http://arxiv.org/abs/0707.3366

Nuclear and High Energy PhysicsPhotonBethe–Salpeter equationHigh Energy Physics::LatticeNuclear TheoryFOS: Physical sciences[PACS] Relativistic models of nucleiPartícules (Física nuclear)PionHigh Energy Physics - Phenomenology (hep-ph)Nambu–Jona-Lasinio modelBound stateVirtual Compton-scatteringCovariant transformation[PACS] Photon and charged-lepton interactions with hadrons[PACS] Bound and unstable statesMathematical physicsQuantum chromodynamicsPhysicsHigh Energy Physics::PhenomenologyGeneralized Parton distributions[PACS] Bound and unstable states; Bethe-Salpeter equations[PACS] Other nonperturbative calculations in QCDHigh Energy Physics - PhenomenologyAmplitudeQuantum electrodynamicsBethe-Salpeter equationsFísica nuclear
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Solution of universal nonrelativistic nuclear DFT equations in the Cartesian deformed harmonic-oscillator basis. (IX) HFODD (v3.06h) : a new version …

2021

We describe the new version (v3.06h) of the code HFODD that solves the universal nonrelativistic nuclear DFT Hartree-Fock or Hartree-Fock-Bogolyubov problem by using the Cartesian deformed harmonic-oscillator basis. In the new version, we implemented the following new features: (i) zero-range three- and four-body central terms, (ii) zero-range three-body gradient terms, (iii) zero-range tensor terms, (iv) zero-range isospin-breaking terms, (v) finite-range higher-order regularized terms, (vi) finite-range separable terms, (vii) zero-range two-body pairing terms, (viii) multi-quasiparticle blocking, (ix) Pfaffian overlaps, (x) particle-number and parity symmetry restoration, (xi) axializatio…

Nuclear and High Energy Physics[PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th]Nuclear Theoryharmonic-oscillator basisMEAN-FIELDFOS: Physical sciencesPfaffianPART114 Physical sciences01 natural sciencesSeparable spacelaw.inventionNuclear Theory (nucl-th)värähtelytlawFINITE-RANGEBOGOLYUBOV EQUATIONS0103 physical sciencesCartesian coordinate systemTensornuclear DFT010306 general physicsHarmonic oscillatorMathematical physicsPARAMETRIZATIONPhysicsBasis (linear algebra)010308 nuclear & particles physicstiheysfunktionaaliteoriatietokoneohjelmatParity (physics)HARTREE-FOCK EQUATIONSHFODDGROUND-STATEPairingnumeerinen analyysiFORCESydinfysiikka
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Exotic states in the S=1 N-pi-K system and low-lying 1/2+ S=-1 resonances

2010

In this manuscript we discuss about our study of the $N \pi \bar{K}$ and the NπK systems made by solving the Faddeev equations with the two-body t-matrices obtained by solving the Bethe-Salpeter equations with the potentials obtained from chiral dynamics. In the strangeness = -1 case, we found that all the Λ and Σ resonances listed by the particle data group, with spin-parity 1/2+ , in the 1550-1800 MeV region get generated due to the involved three-body dynamics. This motivated us to study the strangeness =1 three-body system, i.e., NπK , where we did not find any evidence for the Θ + (1542) but found a broad bump around 1700 MeV which has a κ (800)N structure.

Nuclear physicsPhysicsFaddeev equationsParticle physicsBethe–Salpeter equationPhysicsQC1-999Structure (category theory)Particle Data GroupStrangenessThree-body problemBar (unit)S-matrixEPJ Web of Conferences
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Pion interaction with the trinucleon up to the eta production threshold

1993

Pion elastic, charge exchange scattering and induced eta production on the trinucleon systems are investigated in a coupled-channels approach in momentum space with Fadeev wave functions. The channel $\pi N \rightarrow \eta N$ is included using an isobar model with S-, P-, and D-wave resonances. While the coherent reactions like $^3$He($\pi,\pi)^3$He can be reasonably well reproduced up to $T_{\pi}$=500 MeV, large discrepancies appear for the incoherent processes, $^3$He($\pi^-,\pi^0)^3$H and $^3$He($\pi^-,\eta)^3$H at backward angles and energies above $\Delta$-resonance. In the forward direction the $(\pi,\eta)$ calculations underestimate the experimental measurements very close to thresh…

Nuclear reactionPhysicsElastic scatteringNuclear and High Energy PhysicsFaddeev equationsMesonNuclear Theory010308 nuclear & particles physicsComputer Science::Information RetrievalHadronNuclear TheoryFOS: Physical sciencesElementary particle01 natural sciences7. Clean energyNuclear physicsNuclear Theory (nucl-th)PionQuantum mechanics0103 physical sciences010306 general physicsWave functionNuclear Experiment
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Explicit solutions for second-order operator differential equations with two boundary-value conditions. II

1992

AbstractBoundary-value problems for second-order operator differential equations with two boundary-value conditions are studied for the case where the companion operator is similar to a block-diagonal operator. This case is strictly more general than the one treated in an earlier paper, and it provides explicit closed-form solutions of boundary-value problem in terms of data without increasing the dimension of the problem.

Numerical AnalysisAlgebra and Number TheoryMathematical analysisSemi-elliptic operatorp-LaplacianOrder operatorDiscrete Mathematics and CombinatoricsBoundary value problemGeometry and TopologyC0-semigroupDifferential algebraic geometryTrace operatorNumerical partial differential equationsMathematicsLinear Algebra and its Applications
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Laminar flow through fractal porous materials: the fractional-order transport equation

2015

Abstract The anomalous transport of a viscous fluid across a porous media with power-law scaling of the geometrical features of the pores is dealt with in the paper. It has been shown that, assuming a linear force–flux relation for the motion in a porous solid, then a generalized version of the Hagen–Poiseuille equation has been obtained with the aid of Riemann–Liouville fractional derivative. The order of the derivative is related to the scaling property of the considered media yielding an appropriate mechanical picture for the use of generalized fractional-order relations, as recently used in scientific literature.

Numerical AnalysisApplied MathematicsMathematical analysisLaminar flowViscous liquidFractional calculuFractional calculusPhysics::Fluid DynamicsTransport equationFractals; Fractional calculus; Transport equations; Modeling and Simulation; Numerical Analysis; Applied MathematicsFractalModeling and SimulationFractalSettore ICAR/08 - Scienza Delle CostruzioniConvection–diffusion equationPorosityPorous mediumNumerical AnalysiScalingMathematicsCommunications in Nonlinear Science and Numerical Simulation
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A note on the uniqueness and attractive behavior of solutions for nonlinear Volterra equations

2001

In this paper we prove that positive solutions of some nonlinear Volterra integral equations must be locally bounded and global attractors of positive functions. These results complete previous results about the existence and uniqueness of solutions and their attractive behavior.

Numerical AnalysisApplied MathematicsMathematical analysisVolterra equationsNonlinear volterra integral equationsVolterra integral equationNonlinear systemsymbols.namesakeBounded functionAttractorsymbolsUniquenessMatemàticaMathematics
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