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Indeed two comments can be done. The first one concerns Cosmology, more precisely the standard... more Indeed two comments can be done.
The first one concerns Cosmology, more precisely the standard model. At very
large scale the Universe is supposed to be described by the FLRW metric which
depends on two parameters, the curvature KKK and the scale factor aaa, but the
following substitutions (K,a,r)(K,a,r)(K,a,r) into $(\beta K, \beta^{1/2} a,
\beta^{-1/2}r)$ with beta>0\beta >0beta>0 leave invariant the metric. Therefore there is
one degree of freedom used to fix the value of the scale factor at a given
date. Then the curvature KKK is the only adjustable parameter to astrophysical
data and one can show that a negative value in the order of −0,2.10−56cm−2-0,2.10^{-56}cm^{-2}−0,2.10−56cm−2 is sufficient to account for characteristics of a
universe with a baryonic density of about 0,5.10−30g/cm30,5.10^{-30}g/cm^{3} 0,5.10−30g/cm3, i.e. without
introducing an hypothetical dark matter, but an equation of state relating
pressure and density of the cosmic fluid is not postulated, the theoretical
cosmic fluid being not a terrestrial fluid.
The second remark deals with galaxies described by a static and spherically
symmetric metric using two functions AAA and BBB of the radial coordinate. The
function AAA is related to the density of the fluid and BBB to its pressure,
this metric is a generalization of the K\"ottler's one. By studying geodesics
one shows that BBB is directly correlated with the rotation speed of a test
particule and hence can be modelled to the rotation curves of galaxies which
become data of the problem by a priori forgetting any equation of state. Again,
it is unnecessary to introduce some hallo of dark matter to account for
astrophysical data.
Finally a cosmological unit system using the cosmological constant is
proposed.
Lecture Notes in Physics, 1978
ABSTRACT Without Abstract
Contemporary Mathematics, 1997
Il Nuovo Cimento A Series 10, 1966
We give a sufficient set of conditions for the validity of the regularization method in potential... more We give a sufficient set of conditions for the validity of the regularization method in potential scattering for any linear momentum /~ and angular momentum l.
Il Nuovo Cimento A, 1975
We show that a significative conneetion can be established between the three nonconjugatc ten-dim... more We show that a significative conneetion can be established between the three nonconjugatc ten-dimensional subalgebras of the eonformal algebra and three nonconjugate eleven-dimensional subalgebras of the extended SchrSdinger algebra. This connection is performed through the Wigner-Inonfi contraction-extension procedure and makes appear, besides the well-known correspondence between the free relativistic particle and the free nonrel~tivistie one, an interesting relation between the concept of a free relativistic particle in spaces of constant curvature and the concept of a nonrelativistio one in specifical external fields.
The two-photon production cross section in the Compton effect (i.e., the ; double Compton effect)... more The two-photon production cross section in the Compton effect (i.e., the ; double Compton effect) is established by the use of quantum electrodynamics. The ; method used permits the polarization state of the scattered photons to be studied. ; (tr-auth);
Attempts to show the experimental evidence of the double Compton effect are described. These expe... more Attempts to show the experimental evidence of the double Compton effect are described. These experiments are of two sorts, namely those based on kinematical properties and those that study the differential cross section. (auth)
Comptes Rendus de l Académie des Sciences - Series I - Mathematics
Annales des Sciences Mathematiques du Quebec
The geometrical structures (in the sense of E. Cartan) are analyzed which underlie the gravitatio... more The geometrical structures (in the sense of E. Cartan) are analyzed which underlie the gravitational radiation phenomenon. Among the results are : - the introduction of the adapted frame bundle to a congruence of isotropic hypersurfaces in a Lorentzian manifold, - the description of the reduced frame bundle which admits a unique radiation connection induced from the ambiant space-time one, - the determination of the automorphisms of an integrable radiation structure, - the repercussions of the geometry on the shape of the stress-energy tensor in the Einstein's field equations.
Indeed two comments can be done. The first one concerns Cosmology, more precisely the standard... more Indeed two comments can be done.
The first one concerns Cosmology, more precisely the standard model. At very
large scale the Universe is supposed to be described by the FLRW metric which
depends on two parameters, the curvature KKK and the scale factor aaa, but the
following substitutions (K,a,r)(K,a,r)(K,a,r) into $(\beta K, \beta^{1/2} a,
\beta^{-1/2}r)$ with beta>0\beta >0beta>0 leave invariant the metric. Therefore there is
one degree of freedom used to fix the value of the scale factor at a given
date. Then the curvature KKK is the only adjustable parameter to astrophysical
data and one can show that a negative value in the order of −0,2.10−56cm−2-0,2.10^{-56}cm^{-2}−0,2.10−56cm−2 is sufficient to account for characteristics of a
universe with a baryonic density of about 0,5.10−30g/cm30,5.10^{-30}g/cm^{3} 0,5.10−30g/cm3, i.e. without
introducing an hypothetical dark matter, but an equation of state relating
pressure and density of the cosmic fluid is not postulated, the theoretical
cosmic fluid being not a terrestrial fluid.
The second remark deals with galaxies described by a static and spherically
symmetric metric using two functions AAA and BBB of the radial coordinate. The
function AAA is related to the density of the fluid and BBB to its pressure,
this metric is a generalization of the K\"ottler's one. By studying geodesics
one shows that BBB is directly correlated with the rotation speed of a test
particule and hence can be modelled to the rotation curves of galaxies which
become data of the problem by a priori forgetting any equation of state. Again,
it is unnecessary to introduce some hallo of dark matter to account for
astrophysical data.
Finally a cosmological unit system using the cosmological constant is
proposed.
Lecture Notes in Physics, 1978
ABSTRACT Without Abstract
Contemporary Mathematics, 1997
Il Nuovo Cimento A Series 10, 1966
We give a sufficient set of conditions for the validity of the regularization method in potential... more We give a sufficient set of conditions for the validity of the regularization method in potential scattering for any linear momentum /~ and angular momentum l.
Il Nuovo Cimento A, 1975
We show that a significative conneetion can be established between the three nonconjugatc ten-dim... more We show that a significative conneetion can be established between the three nonconjugatc ten-dimensional subalgebras of the eonformal algebra and three nonconjugate eleven-dimensional subalgebras of the extended SchrSdinger algebra. This connection is performed through the Wigner-Inonfi contraction-extension procedure and makes appear, besides the well-known correspondence between the free relativistic particle and the free nonrel~tivistie one, an interesting relation between the concept of a free relativistic particle in spaces of constant curvature and the concept of a nonrelativistio one in specifical external fields.
The two-photon production cross section in the Compton effect (i.e., the ; double Compton effect)... more The two-photon production cross section in the Compton effect (i.e., the ; double Compton effect) is established by the use of quantum electrodynamics. The ; method used permits the polarization state of the scattered photons to be studied. ; (tr-auth);
Attempts to show the experimental evidence of the double Compton effect are described. These expe... more Attempts to show the experimental evidence of the double Compton effect are described. These experiments are of two sorts, namely those based on kinematical properties and those that study the differential cross section. (auth)
Comptes Rendus de l Académie des Sciences - Series I - Mathematics
Annales des Sciences Mathematiques du Quebec
The geometrical structures (in the sense of E. Cartan) are analyzed which underlie the gravitatio... more The geometrical structures (in the sense of E. Cartan) are analyzed which underlie the gravitational radiation phenomenon. Among the results are : - the introduction of the adapted frame bundle to a congruence of isotropic hypersurfaces in a Lorentzian manifold, - the description of the reduced frame bundle which admits a unique radiation connection induced from the ambiant space-time one, - the determination of the automorphisms of an integrable radiation structure, - the repercussions of the geometry on the shape of the stress-energy tensor in the Einstein's field equations.