scholarly journals The Perturbation of Material Density in F(R) Modified Gravity of Polynomial Exponential Form

2019 ◽  
Keyword(s):  
Modified Gravity ◽  
Exponential Form ◽  
Material Density

scholarly journals The Perturbation of Material Density in f(R) Modified Gravity of Polynormal Exponential Form

10.29007/xqpk ◽  
2020 ◽  
Author(s):  
Van On Vo
Keyword(s):  
Cosmological Model ◽  
Modified Gravity ◽  
Linear Perturbation ◽  
Exponential Form ◽  
Material Density ◽  
Gravitational Model ◽  
Standard Cosmological Model ◽  
The Difference ◽  
Evolutionary Aspects ◽  
The Universe

In this paper, we investigate the linear perturbation of the material density of the universe in f(R) modified gravity of polynomial exponential form on the scale of distance below the cosmic horizon (sub-horizon). The results show that the model for the evolutionary aspects of the universe is slightly different from that in the standard cosmological model of ΛCDM. They can be used to show the difference between this modified gravitational model with the standard cosmological model of ΛCMD and other cosmological models. We also investigate the ration Ψ/ Φ and Geff / GN in the model and show that they are within allowable limits of experiments.

scholarly journals Cosmic inflation in some viable modified models of f(R) gravity of polynomial-exponential form

2021 ◽  
Vol 2070 (1) ◽  
pp. 012049
Author(s):  
Vo Van On ◽  
Nguyen Hai Dang
Keyword(s):  
Modified Gravity ◽  
Exponential Form ◽  
Cosmic Inflation ◽  
Inflation Scenario

Abstract In this paper, we present the cosmic inflation scenario in some viable models of the f(R) modified gravity of polynomial-exponential form. Results show that the magnitude of the parameter β in these viable models is at the order of 5.67x10–76 and the time of inflation is at the order of 4.6 x 10–35 s.

Specimen Collection Effect in Scanning Electron Microscopy Images

1972 ◽  
Vol 30 ◽  
pp. 448-449
Author(s):  
J. Temple Black ◽  
Jose Guerrero
Keyword(s):  
Surface Morphology ◽  
Secondary Electron Emission ◽  
Secondary Electrons ◽  
Charge Effects ◽  
Material Density ◽  
Specimen Collection ◽  
The Subject ◽  
Curved Paths ◽  
Subject Material ◽  
Microscopy Images

In the SEM, contrast in the image is the result of variations in the volume secondary electron emission and backscatter emission which reaches the detector and serves to intensity modulate the signal for the CRT's. This emission is a function of the accelerating potential, material density, chemistry, crystallography, local charge effects, surface morphology and especially the angle of the incident electron beam with the particular surface site. Aside from the influence of object inclination, the surface morphology is the most important feature In producing contrast. “Specimen collection“ is the name given the shielding of the collector by adjacent parts of the specimen, producing much image contrast. This type of contrast can occur for both secondary and backscatter electrons even though the secondary electrons take curved paths to the detector-collector.Figure 1 demonstrates, in a unique and striking fashion, the specimen collection effect. The subject material here is Armco Iron, 99.85% purity, which was spark machined.

Study of a Restricted Modified Gravity on astrophysical and cosmological scales

2019 ◽  
Vol 19 (2) ◽  
pp. 447-453
Author(s):  
Nasim Derakhshanian ◽  
Amir Ghalee ◽  
◽  
Keyword(s):  
Modified Gravity

Editorial [Dark Energy and Modified Gravity]

2010 ◽  
Vol 3 (2) ◽  
pp. 12-12
Author(s):  
S. Nojiri ◽  
S. D. Odintsov
Keyword(s):  
Dark Energy ◽  
Modified Gravity

scholarly journals Black hole solutions in modified gravity induced by quantum metric fluctuations

2021 ◽  
Vol 31 ◽  
pp. 100756
Author(s):  
Jin-Zhao Yang ◽  
Shahab Shahidi ◽  
Tiberiu Harko ◽  
Shi-Dong Liang
Keyword(s):  
Black Hole ◽  
Modified Gravity ◽  
Black Hole Solutions ◽  
Metric Fluctuations

scholarly journals Dimensional Analysis of the Effect of SLM Parameters on Surface Roughness and Material Density

Procedia CIRP ◽  
2020 ◽  
Vol 95 ◽  
pp. 115-120
Author(s):  
T. Zakrzewski ◽  
J. Kozak ◽  
M. Witt ◽  
M. Dębowska-Wąsak
Keyword(s):  
Surface Roughness ◽  
Dimensional Analysis ◽  
Material Density
Sign in / Sign up

Export Citation Format

Share Document