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مرکز اطلاعات علمی SID1
اسکوپوس
دانشگاه غیر انتفاعی مهر اروند
ریسرچگیت
strs
Author(s): 

RIAZI N.

Issue Info: 
  • Year: 

    2002
  • Volume: 

    3
  • Issue: 

    2
  • Pages: 

    133-138
Measures: 
  • Citations: 

    0
  • Views: 

    1120
  • Downloads: 

    393
Abstract: 

There are several observational evidences for the existence of DARK MATTER in the universe. More than about 90% of the MATTER in the universe is in a form which is not directly observable. If the DARK MATTER is in the form of weakly interacting massive particles (WIMPs) or cosmions, part of it is captured by the Sun, other stars, and even planets. In this paper, some basic ideas of the cosmion hypothesis are presented and the abundance and the coefficient of thermal energy transport by WIMPs are calculated, using an approximate method.

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Author(s): 

GIBSON C.H.

Issue Info: 
  • Year: 

    2008
  • Volume: 

    1
  • Issue: 

    2
  • Pages: 

    1-8
Measures: 
  • Citations: 

    0
  • Views: 

    100793
  • Downloads: 

    37520
Abstract: 

COLD DARK MATTER hierarchical clustering (CDMHC) cosmology based on the Jeans (1902) criterion for gravitational instability gives predictions about the early universe contrary to fluid mechanics and observations. Jeans neglected viscosity, diffusivity, and turbulence: factors that determine gravitational structure formation and contradict small structures (CDM halos) forming from non-baryonic DARK MATTER particle candidates. From hydro-gravitational-dynamics (HGD) cosmology, viscous-gravitational fragmentation produced supercluster (1046kg), cluster, and galaxy (1042kg) mass clouds in the primordial plasma with the large fossil density (r0=3×10-17 kg m-3) of the first fragmentation at 1012 s, and a linear and spiral clump morphology reflecting stretching-compression rates near vortex lines of the plasma turbulence at the 1013 s plasma-gas transition. Gas proto-galaxies fragmented into proto-globular-star-cluster mass (1036 kg) clumps of proto-planet clouds, presently frozen as earth-mass (1024-25 kg) Jovian planets of the baryonic DARK MATTER, about 30.000.000 rogue plants per star. All stars from these planets. They appear in planetary nebulae and are misinterpreted as DARK energy. Observations contradict the CDMHCC prediction of large explosive population III first stars at 1016 s, but support the gentle formation of small population II first stars at 1013 s in globule star-clusters from HGD.

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Author(s): 

ALAVI S.A.A. | SALEHI T.

Issue Info: 
  • Year: 

    2017
  • Volume: 

    16
  • Issue: 

    4
  • Pages: 

    389-392
Measures: 
  • Citations: 

    0
  • Views: 

    453
  • Downloads: 

    243
Abstract: 

First، singlet DARK MATTER annihilation into pair charged fermions and pair W ± bosons was studied to the first order of non-commutativity parameter in perturbative model. Our results are different from the results reported in some previous studies. Then the problem is formulated in θ-exact non-commutative space-time and non-perturbative model، then the exact results are presented.

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گارگاه ها آموزشی
Author(s): 

SOBOUTI Y.

Issue Info: 
  • Year: 

    2005
  • Volume: 

    5
  • Issue: 

    3
  • Pages: 

    113-119
Measures: 
  • Citations: 

    0
  • Views: 

    951
  • Downloads: 

    403
Abstract: 

Allowing the energy of a gravitational field to serve partially as its own source allows gravitating bodies to exhibit stronger fields, as if they were more massive. Depending on degree of compaction of the body, the field could be one to five times larger than the Newtonian field. This is a comfortable range of increase in field strength and may prove to be of convenience in the study of velocity curves of spirals, of velocity dispersions in clusters of galaxies and in interpreting the Tully-Fisher or Faber-Jackson relations in galaxies or systems of galaxies. The revised gravitation admits of superposition principle but only approximately in systems whose components are widely separated. The revised dynamics admits of the equivalence principle in that, the effective force acting on a test particle is derived from a potential, and could be elimhnated in a freely falling frame of reference.

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Author(s): 

WILLIAMS P.E.

Journal: 

APEIRON

Issue Info: 
  • Year: 

    2008
  • Volume: 

    15
  • Issue: 

    -
  • Pages: 

    294-313
Measures: 
  • Citations: 

    452
  • Views: 

    19142
  • Downloads: 

    27293
Keywords: 
Abstract: 

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Author(s): 

FRIEDMAN N. | KAPLAN A. | DAVIDSON N.

Issue Info: 
  • Year: 

    2002
  • Volume: 

    48
  • Issue: 

    -
  • Pages: 

    99-151
Measures: 
  • Citations: 

    470
  • Views: 

    19292
  • Downloads: 

    30995
Keywords: 
Abstract: 

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strs
Author(s): 

REZAEI Z. | ALIZADEH T.

Issue Info: 
  • Year: 

    2019
  • Volume: 

    19
  • Issue: 

    2
  • Pages: 

    455-461
Measures: 
  • Citations: 

    0
  • Views: 

    359
  • Downloads: 

    260
Abstract: 

In this paper, we examine the singlet scalar DARK MATTER annihilation to becoming the Standard Model particles in the non-commutative space. In the recent decades, many candidates of DARK MATTER have been offered, but our information about the nature of DARK MATTER is still limited. There are such particle candidates as scalar matetr, fermion, boson, gauge boson, etc.; however, they have neither approved nor rejected. Some complicated models offer many parameters that must be determined. Among these models, the singlet scalar DARK MATTER model is the simplest one that contains just two free parameters to specify. In this paper, we study the singlet scalar DARK MATTER in the noncommutative space, give the scalar DARK MATTER and higgs lagrangian to find their coupling in noncommutative space-time and calculate the cross-section of the scalar DARK MATTER pair annihilation to becoming the standard model particles. It must be noted that there is one extra coupling to explain the DARK MATTER annihilation to becoming the standard model particles in the noncommutative space-time. We investigate the parameter space using the constraint of the thermal average of annihilation cross-section by the velocity. This is the first research on the DARK MATTER annihilation to becoming the standard model particles through the higgs channel in the noncommutative space.

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Author(s): 

REZAEI ZEINAB

Issue Info: 
  • Year: 

    2018
  • Volume: 

    8
  • Issue: 

    17
  • Pages: 

    41-50
Measures: 
  • Citations: 

    0
  • Views: 

    675
  • Downloads: 

    247
Abstract: 

In this paper, we investigate the effect of neutron MATTER equation of state on the structure of halo of DARK MATTER and the distribution of DARK MATTER in neutron star using the relativistic two-fluid formalism in the DARK-MATTER admixed neutron star. Applying the equation of state related to the free fermionic gas as DARK MATTER equation of state, we calculate the structure of DARK-MATTER admixed neutron star within different models of Skyrme interaction for the neutron MATTER, SLy230a, SLy230b, SkM*. Our results indicate that the mass-radius relation depends on the model of interaction. In addition, our calculations confirm that the neutron MATTER equation of state affects the size of DARK MATTER and neutron MATTER cores. The results show that the surface gravitational redshift depends on the neutron MATTER equation of state.

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Author(s): 

RAHIMI M. | HAGHIGHAT M.

Issue Info: 
  • Year: 

    2018
  • Volume: 

    18
  • Issue: 

    2
  • Pages: 

    177-180
Measures: 
  • Citations: 

    0
  • Views: 

    556
  • Downloads: 

    221
Abstract: 

In the ADM the DARK MATTERs interact with the ordinary MATTERs exclusively through the electromagnetic anapoles. Meanwhile, the only allowed electromagnetic form factor for the spin 1/2 Majorana fermions is the anapole one. We study the electromagnetic interaction of the Majorana neutrinos in non-commutative standard model (NCSM) and the Lorentz violated extension of the standard model (SME). Consequently, we obtain the anapole form factors in the both models. Comparing the obtained results in the SME with the experimental data only put a bound on d 00-parameter among the SME-parameters which is of the order of 0. 04. We estimate a bound of the order of 0. 5 TeV on the parameter of non-commutativity.

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Author(s): 

Issue Info: 
  • Year: 

    2020
  • Volume: 

    39
  • Issue: 

    1
  • Pages: 

    0-0
Measures: 
  • Citations: 

    235
  • Views: 

    1888
  • Downloads: 

    22345
Keywords: 
Abstract: 

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