constant energy density
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Author(s):  
Jae-Kwang Hwang

Space-time evolution of our universe is explained by using the 3-dimensional quantized space model (TQSM) based on the 4-dimensional (4-D) Euclidean space. The energy (E = cDtDV), charges and energy density (|q| = r = cDt) and absolute time (ct) are newly defined based on the 4-D Euclidean space. The photon flat space with the constant energy density of r = cDtq is proposed as the dark energy (DE). The dark energy is separated into the n DE and photon DE which create the new photon spaces with the constant energy density of r = cDtq. The v DE is from the n pair production by the CPT symmetry and the photon DE is from the photon space pair production by the T symmetry. The vacuum energy crisis and Hubble’s constant puzzle are explained by the photon space with the n DE and photon DE. The big bang and inflation of the primary black hole is connected to the accelerated space expansion and big collapse of the photon space through the universe evolution. The big bang from the nothing is the pair production of the matter universe with the positive energy and the partner anti-matter universe with the negative energy from the CPT symmetry. Our universe is the matter universe with the negative charges of electric charge (EC), lepton charge (LC) and color charge (CC). This first universe is made of dark matter -, lepton -, and quark - primary black holes with the huge negative charges which cause the Coulomb repulsive forces much bigger than the gravitational forces. The huge Coulomb forces induce the inflation of the primary black holes, that decay to the super-massive black holes and particles.


2021 ◽  
Author(s):  
Tee-How Loo ◽  
Avik De ◽  
Sanjay Mandal ◽  
P. K. Sahoo

Abstract In the present paper we examine a projectively flat spacetime solution of F(R)-gravity theory. It is seen that once we deploy projective flatness in the geometry of the spacetime, the matter field has constant energy density and isotropic pressure. We then make the condition weaker and discuss the effects of projectively harmonic spacetime geometry in F(R)-gravity theory and show that the spacetime in this case reduces to a generalised Robertson-Walker spacetime with a shear, vorticity, acceleration free perfect fluid with a specific form of expansion scalar presented in terms of the scale factor. Role of conharmonic curvature tensor in the spacetime geometry is also briefly discussed. Some analysis of the obtained results are conducted in terms of couple of F(R)-gravity models.


Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 828
Author(s):  
Jianqi Liu ◽  
Xin Liu ◽  
Jiayao Chen ◽  
Xianying Li ◽  
Tianpeng Ma ◽  
...  

Toluene removal by double dielectric barrier charge (DDBD) plasma combined with a ZrMnFe/Sepiolite (SEP) catalyst was investigated and compared with the results from Fe/SEP, Mn/SEP and MnFe/SEP ones. All the catalysts were prepared by the impregnation method and characterized by XRD, BET, ICP, SEM, TEM, H2-TPR and XPS. The effect of catalysts on toluene degradation efficiency, carbon balance, CO2 selectivity and residual O3 concentration was studied. The experimental results indicated that the ZrMnFe/SEP catalyst presented the best catalytic performance. This is because of the high content of lattice oxygen contained in its surface, owing to the addition of Zr. When the SIE was 740 J/L, the highest toluene removal efficiency (87%), carbon balance (93%) and CO2 selectivity (51%) were obtained. The ZrMnFe/SEP catalyst had a better ozone inhibition effect than other catalysts. The catalyst has good stability, which the toluene removal efficiency, carbon balance and CO2 selectivity did not decrease significantly after 36 h of work at a constant energy density. The results indicated that the ZrMnFe/SEP catalyst is an efficient catalyst for degradation of toluene by plasma-catalyst measures.


Author(s):  
Michael Paul Gough

Stellar heated gas and dust has a universe total entropy/information content of ~10^86 bits. At typical temperatures ~10^7 the equivalent N kB T ln(2) information energy ~10^70 J is comparable to the mc2 of the universe’s ~10^53 kg of baryons. At low red-shifts, z<1.35 this dark energy contribution provides a near constant energy density, with an equation of state parameter, w=-1.03±0.05, effectively emulating a cosmological constant to within 1.8% in Hubble parameter, H(a). Earlier, z>1.35, the information energy contribution was phantom, w=-1.82±0.08. This dark energy differs from the cosmological constant by △w0= -0.03±0.05 and △wa= -0.79±0.08, sufficient to account for the value of the ‘Hubble Tension’ between early and late universe H0 values. An information energy model will fit most observations as well as Ʌ, and also resolve Hubble tension and cosmological coincidence problems. Furthermore, information energy could also account for many effects previously attributed to dark matter.


2020 ◽  
Vol 229 (22-23) ◽  
pp. 3537-3550
Author(s):  
Christian Spieles ◽  
Marcus Bleicher

AbstractWe investigate hadronic particle spectra and flow characteristics of heavy-ion reactions in the FAIR/NICA energy range of 1 AGeV ≤ Elab ≤ 10 AGeV within a relativistic ideal hydrodynamic one-fluid approach. The particlization is realized by sampling the Cooper-Frye distribution for a grand canonical hadron gas on a hypersurface of constant energy density. Results of the hydrodynamic calculations for different underlying equations of state are presented and compared with experimental data and microscopic transport simulations. The sensitivity of the approach to physical model inputs concerning the initial state and the particlization is studied.


2020 ◽  
Vol 04 (04) ◽  
pp. 2050009
Author(s):  
Mahendra Goray ◽  
Ramesh Naidu Annavarapu

Several concepts have been proposed to explain the mystic nature of dark energy and the accelerating universe. Among them, geometrical dark energy is one such class that is based on the scalar curvature, and another type is based upon the “equation of state”. Also, another model suggests that neutrino rest-mass interaction is responsible for the “equation of state” with constant energy density. In this work, we have investigated another dark energy approach which is based on the illusive mass of the photon and a new geometrical perspective. Photon reveals its illusive mass behavior when it interacts with the surface of matter, i.e., photon manifests itself into different forms of mass. Hence, photon might hide some of its energy due to this new characteristic. This photon’s energy is embedded in the form of a curvature dependent complex number and could be considered as the new form of dark energy. Hence, we propose that the dark energy might be hiding in the photon’s illusive form and could pave the way towards unravelling the secrets of the dark energy of the universe and hence the accelerating universe.


Author(s):  
M. M. Praveena ◽  
C. S. Bagewadi ◽  
M. R. Krishnamurthy

We study solitons of almost pseudo symmetric Kählerian space-time manifold. It is considered that different curvature tensors like projective, conharmonic and conformal curvature tensors in almost pseudo symmetric Kählerian space-time manifolds are flat. It is shown that solitons are steady, expanding or shrinking under different relations of isotropic pressure, the cosmological constant, energy density and gravitational constant..


2020 ◽  
Vol 98 (10) ◽  
pp. 917-928
Author(s):  
M. Campista ◽  
R. Chan ◽  
M.F.A. da Silva ◽  
O. Goldoni ◽  
V.H. Satheeshkumar ◽  
...  

The Einstein–Aether (EA) theory belongs to a class of modified gravity theories characterized by the introduction of a time-like unit vector field called aether. In this scenario, a preferred frame arises as a natural consequence of a broken Lorentz invariance. In the present work, we have obtained and analyzed some exact solutions allowed by this theory for two particular cases of a perfect fluid, both with Friedmann–Lemaître–Robertson–Walker symmetry: (i) a fluid with constant energy density (p = –ρ0) and (ii) a fluid with zero energy density (ρ0 = 0) corresponding to the vacuum solution with and without cosmological constant (Λ), respectively. Our solutions show that the EA and general relativity (GR) theories only differ in coupling constants. This difference is clearly shown because of the existence of singularities that are not in GR theory. This characteristic appears in the solutions with p = –ρ0 as well as with ρ0 = 0, where this last one depends only on the aether field. Furthermore, we consider the term of the EA theory in the Raychaudhuri equation and discuss the meaning of the strong energy condition in this scenario and found that this depends on the aether field. The solutions admit an expanding or contracting system. Bounce, singular, constant, and accelerated expansion solutions were also obtained, exhibiting the richness of the EA theory from the dynamic point of view of a collapsing system or of a cosmological model. The analysis of energy conditions, considering an effective fluid, shows that the term of the aether contributes significantly for the accelerated expansion of the system for the case in which the energy density is constant. On the other hand, for the vacuum case (ρ0 = 0), the energy conditions are all satisfied for the aether fluid.


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