6,327 research outputs found
Vacuum quantum effect for curved boundaries in static Robertson--Walker spacetime
The energy-momentum tensor for a massless conformally coupled scalar field in
the region between two curved boundaries in static Robertson--Walker
spacetime is investigated. We assume that the scalar field satisfies the
Dirichlet boundary condition on the boundaries. Robertson--Walker space
is conformally related to the Rindler space, as a result we can obtain vacuum
expectation values of energy-momentum tensor for conformally invariant field in
Robertson--Walker space from the corresponding Rindler counterpart by the
conformal transformation.Comment: 7 pages, no figures; Clarifying comments added, no physics changed,
version to appear in PLB (2009
Application of EFT at Thermal Energies
We have been evaluated some observables of n-d systems by using pionless
Effective Field Theory(\EFTNoPion) and insertion of the three-body force up to
next-to-next to leading order(NLO). The evaluated data has been compared
with experimental and the three-nucleon calculation of the total cross section
with modern realistic two- and three-nucleon forces AV18/UrbIX potential models
calculations.Comment: 3 pages, 1 figure and 1 table. Talk given at 20th European Conference
on Few-Body Problems in Physics (EFB 20), Pisa, Italy, 10-14 Sep 200
Tetraquarks as Diquark Antidiquark Bound Systems
In this paper, we study four-body systems consisting of diquark antidiquark,
and we analyze diquark-antidiquark in the framework of a two body (pseudo
point) problem. We solve Lippman Schwinger equation numerically for charm
diquark antidiquark systems and find the eigenvalues to calculate the binding
energies and masses of heavy tetraquarks with hidden charms. Our results are in
good agreement with theoretical and experimental data
On a type of exponential functional equation and its superstability in the sense of Ger
In this paper, we deal with a type exponential functional equation as follows
where and are two real valued functions on a
commutative semigroup. Our aim of this paper is to proved that the above
functional equation in the sense of Ger is superstable
The relation between non-commutative and Finsler geometry in Horava-Lifshitz black holes
In this paper we employ the Horava-Lifshitz black holes solutions and obtain
the corresponding Hamiltonian. It helps us to take new variables and it will be
written by harmonic oscillator form. This leads us to apply non-commutative
geometry to the new Hamiltonian and obtain the corresponding Lagrangian. And
then, we take some information from Finsler geometry and write the Lagrangian
of the different kinds of Horava-Lifshitz black holes. We show that the
corresponding Lagrangian in non-commutative and Finsler geometry for above
mentioned black holes completely coincidence together with some specification
of parameters. But in case of rotation, the place of center of mass energy
completely different, so the particle goes to inside of black hole rapidly
without falling into singularity. So in that case, two Lagrangians cover each
other at Comment: 15 page
The Lagrangian of charged test particle in Horava-Lifshitz black hole and deformed phase space
In this paper, we use deformation approach and obtain the corresponding
Lagrangian of charged test particle. Also, we show the effect of NC parameters
on the Lagrangian of test particle in HL background with charge and without
charge. Also, we see in case of and without charge, the deformed
and non-deformed Lagrangian will be same. Also in case of and
with charge will be the same but the charge or field need some scaling.
Finally, We show that two theories in case of with charge is
completely different. It means that in case of NC geometry in addition to have
time components of field we have and components.Comment: 9 page
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