scholarly journals Dark matter as a dynamic effect due to a non-minimal gravitational coupling with matter (II): Numerical results

2010 ◽  
Vol 222 ◽  
pp. 012011 ◽  
Author(s):  
J Páramos ◽  
O Bertolami
Keyword(s):  
Dark Matter ◽  
Dynamic Effect ◽  
Numerical Results ◽  
Gravitational Coupling

scholarly journals Constraining the gravitational coupling of axion dark matter at LIGO

2020 ◽  
Vol 102 (5) ◽  
Author(s):  
Sunghoon Jung ◽  
TaeHun Kim ◽  
Jiro Soda ◽  
Yuko Urakawa
Keyword(s):  
Dark Matter ◽  
Gravitational Coupling

scholarly journals Clusters of Galaxies in a Flat CHDM Universe

1998 ◽  
Vol 188 ◽  
pp. 299-299
Author(s):  
A. Habe ◽  
C. Hanyu ◽  
S. Yachi
Keyword(s):  
Dark Matter ◽  
Large Scale ◽  
Large Scale Structure ◽  
Numerical Results ◽  
Clusters Of Galaxies ◽  
Statistical Features ◽  
X Ray ◽  
Numerical Resolution ◽  
Radiative Processes ◽  
The Universe

Cold and hot dark matter (CHDM) model is one of viable models which can reproduce the large scale structure of the universe. HDM may affect structure of clusters of galaxies in CHDM universe. Bryan et al. (1994) gave numerical results of CHDM model that explain some statistical features of X-ray clusters of galaxies, e.g. X-ray luminosiry-temperature realtion, L ∝~ T3.5, without considering radiative processes. However their numerical resolution is insufficient to resolve the cores of X-ray clusters. So, we simulate the formation of clusters in CHDM universe more carefully.

scholarly journals ASTROPHYSICAL AND COSMOLOGICAL CONSTRAINTS ON A SCALE-DEPENDENT GRAVITATIONAL COUPLING

1996 ◽  
Vol 05 (04) ◽  
pp. 363-373 ◽  
Author(s):  
ORFEU BERTOLAMI ◽  
JUAN GARCÍA-BELLIDO
Keyword(s):  
Dark Matter ◽  
Structure Formation ◽  
Gravitational Lensing ◽  
Virial Theorem ◽  
Gravitational Coupling ◽  
Rotation Curves ◽  
Primordial Nucleosynthesis ◽  
Cosmological Constraints ◽  
Binary Pulsars ◽  
Baryonic Dark Matter

We study the phenomenological consequences of the recently proposed idea of a running gravitational coupling on macroscopic scales. When applied to the rotation curves of galaxies, we find that their flatness requires the presence of baryonic dark matter. Bounds on the variation of the gravitational coupling from primordial nucleosynthesis and the change of the period of binary pulsars are analysed. We also study constraints on the variations of G with scale from gravitational lensing and the cosmic virial theorem, as well as briefly discuss the implications of such a scenario for structure formation.

Observation of the Sulphur Atoms in Cu2S Using HREM

1990 ◽  
Vol 48 (1) ◽  
pp. 38-39
Author(s):  
Y.D. Yu ◽  
R. Guan ◽  
K.H. Kuo ◽  
H. Hashimoto
Keyword(s):  
Electron Diffraction ◽  
Tube Wall ◽  
Present Report ◽  
Dynamic Effect ◽  
Glass Tube ◽  
Fluorite Structure ◽  
Point Of View ◽  
Electron Diffraction Analysis ◽  
Sulphur Atom ◽  
Copper Thin Film

We have indicated that the lighter atoms such as oxygen in Cu2O can be observed at the specimen with optimal thicknesses based on the dynamic effect of electron diffraction(1). This rule in principle should hold good for the imaging of other lighter atoms such as sulphur atom in Cu2S. However, this point of view needs further experimentally confirm because up to now only oxygen atoms have been observed in Cu2O and a series of new suboxides of copper and nickel (2). In addition, the sulphur atom is much heavier than oxygen one though is still lighter than copper atom. In the present report we provide such a confirmation.The crystallites of Cu2S shown in Fig.l were obtained by sulfurizing at 300°C of the copper thin film which was sealed in a glass tube with mg sulphur left on the tube wall in a vacuum of about 10-2 Pa. The energy dispersive spectrocscopy analysis indicated that they are the sulfides and the electron diffraction analysis indicated they have anti-fluorite structure.

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