Our Homogeneous and Isotropic Universe on Very Large Scales

2020 ◽  
pp. 451-454
Author(s):  
E. B. Manoukian
Keyword(s):  
Isotropic Universe

Generation of gravitons in the hot uniform and isotropic universe

2001 ◽  
Vol 46 (11) ◽  
pp. 770-772
Author(s):  
S. S. Gershtein ◽  
A. A. Logunov ◽  
M. A. Mestvirishvili
Keyword(s):  
Isotropic Universe

scholarly journals Broadening quantum cosmology with a fractional whirl

2021 ◽  
pp. 2140005
Author(s):  
S. M. M. Rasouli ◽  
S. Jalalzadeh ◽  
P. V. Moniz
Keyword(s):  
Quantum Mechanics ◽  
Fractional Calculus ◽  
Quantum Cosmology ◽  
Cosmological Solution ◽  
Isotropic Universe ◽  
Fractional Quantum ◽  
Stiff Matter ◽  
Standard Quantum

We start by presenting a brief summary of fractional quantum mechanics, as means to convey a motivation towards fractional quantum cosmology. Subsequently, such application is made concrete with the assistance of a case study. Specifically, we investigate and then discuss a model of stiff matter in a spatially flat homogeneous and isotropic universe. A new quantum cosmological solution, where fractional calculus implications are explicit, is presented and then contrasted with the corresponding standard quantum cosmology setting.

The Isotropic Universe

1981 ◽  
Vol 32 (11) ◽  
pp. 365-365
Author(s):  
J M Irvine
Keyword(s):  
Isotropic Universe

scholarly journals RELATIVISTIC HYDRODYNAMICS WITH SOURCES FOR COSMOLOGICAL K-FLUIDS

2005 ◽  
Vol 14 (09) ◽  
pp. 1561-1576 ◽  
Author(s):  
ALBERTO DIEZ-TEJEDOR ◽  
ALEXANDER FEINSTEIN
Keyword(s):  
Variational Principle ◽  
Continuity Equation ◽  
Particle Number ◽  
Source Term ◽  
Velocity Potential ◽  
Fluid Velocity ◽  
Entropy Change ◽  
Relativistic Hydrodynamics ◽  
Isotropic Universe ◽  
Number Of Particles

We consider hydrodynamics with non-conserved number of particles and show that it can be modeled with effective fluid Lagrangians which explicitly depend on the velocity potentials. For such theories, the "shift symmetry" ϕ → ϕ + const leading to the conserved number of fluid particles in conventional hydrodynamics is globally broken and, as a result, the non-conservation of particle number appears as a source term in the continuity equation. The non-conservation of particle number is balanced by the entropy change, with both the entropy and the source term expressed in terms of the fluid velocity potential. Equations of hydrodynamics are derived using a modified version of Schutz's variational principle method. Examples of fluids described by such Lagrangians (tachyon condensate, K-essence) in spatially flat isotropic universe are briefly discussed.

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