Doctorat (Physique)
http://hdl.handle.net/123456789/133124
2018-04-23T00:06:50ZDifférents aspects de la gravitation et de la non commutativité avec quelques applications cosmologiques.
http://hdl.handle.net/123456789/136306
Différents aspects de la gravitation et de la non commutativité avec quelques applications cosmologiques.
Bouhallouf, Habiba; Mebarki, Noureddine
Noncommutative geometry has a very important role in gravitation word because it answers to a lot of questions and explain several phenomena.
With the properties of noncommutative space-time (Seiberg-Witten mapping with Moyal-Weyl ordering), Chiral and gravitational anomalies can be calculated using Fujikawa method in path integral formalism. The result obtained is very important because the non-commutativity gives in this case to space-time a gravitational aspect without a gravitational force where the noncommutativity modifies its Riemannian structure to another one more complicated having a general form of the space-time metric (with torsion and no-metricity).
A contraction of a noncommutative De Sitter SO (4,1) gauge group to the Poincaré (inhomogeneous Lorentz) group ISO (3,1) leads to a deformed gauge fields using the Seiberg-Witten maps, which by explicit calculations gives a deformed metric. This metric (application to FRW space-time) shows several properties of the corresponding black hole. (Calculations and graphs are realized by Maple).
The instability against emission of fermionic particles by the trapping horizon of an evolving black hole is analyzes using the Hamilton-Jacobi method via tunneling effect. This study leads to calculate noncommutative Hawking temperature defined by the surface gravity; this result is purely noncommutative and justified by the graphs showing the variation of Hawking temperature with event horizon and the parameter of noncommutativity.
Finally, Hamilton-Jacobi method via is always useful to study black hole’s radiation via tunneling effect near apparent horizon of Lyra black holes. The correction spending Hawking temperature depends only of the black hole properties (mass) and the structure of Lyra space-time.
2017-12-21T00:00:00ZÉtude de l’effet monopolaire sur les noyaux impair-impairs dans la région de l’étain 132.
http://hdl.handle.net/123456789/136280
Étude de l’effet monopolaire sur les noyaux impair-impairs dans la région de l’étain 132.
Laouet, Nadjet; Benrachi, Fatima
The monopole interaction, which result from the interaction between the magic core and the
valence particles, has a particular interest in the study of nuclear structure and in the
comprehension of the appearance of new magic numbers.
In this thesis, the study is founded on the calculation of the excitation energies and the
electromagnetic properties of odd-odd nuclei with few hole or few particles in addition to the
132Sn core: 128Ag, 130In, 132-134-136-138Sb, 134-136I and 136-138Cs.
Basing on the interactions jj45apn, sn100pn and kh5082 with the model spaces jj45pn, jj55pn
and jj56pn, we have realised some modifications considering the monopole interaction. New
interactions named jj45pnh, snh, cdbm and mkh are then elaborated. The recent values of single
particle and single hole energies are used. The calculations are realised in the frame work of the
nuclear shell model by means of Oxbash nuclear structure code.
The effective charges ep=1.35e and en=0.9e, leading to reproduce the experimental values of
the electromagnetic reduced transition probabilities B(M1) and B(E2) and the moments Q and
µ are used in the calculations.
The getting results are in agreement with the experimental data and better than other calculation
results.
2017-09-07T00:00:00ZEtude phénoménologique du secteur des interactions électrofaibles dans les théories au-delà du Modèle Standard.
http://hdl.handle.net/123456789/136278
Etude phénoménologique du secteur des interactions électrofaibles dans les théories au-delà du Modèle Standard.
Chadou, Ilhem; Mebarki, Noureddine
In this thesis, we have studied the phenomenological study of theories
beyond the standard model, and in particular the non-commutative
standard model, in the electroweak interaction sector.
For thus studied, we have many processes of particle physics:
Production and disintegration of the Higgs boson, production of direct
photons following the proton-antiproton annihilation, electronpositron annihilation in two photons. This essentially allowed us to
analyze the behavior of the non-commutative cross section and to
deduce new bonds on the non-commutativity parameter.
2018-02-08T00:00:00ZEtude des céramiques diélectriques du type BaTiO3-CaTiO3 Influence de différentes additions
http://hdl.handle.net/123456789/136209
Etude des céramiques diélectriques du type BaTiO3-CaTiO3 Influence de différentes additions
Bezzi, Tarek; Barama, S. E.
In this work we are concerned with the preparation and characterisation of BaTiO3 - CaTiO3 –B2O3
nonlinear dielectric materials.
Samples of (1-x) BaTiO3 +xCaTiO3 +y B2O3 type (with x=0.3; 0.7 and 0.01≤y≤0.03) were
elaborated by sintering at various temperatures (1200, 1250, 1300 and 1350°C respectively) during 03h.
The obtained results showed an improvement in the relative density in the case of samples containing 1%
B2O3. At the opposite, the relative density of the sintered samples decreases for higher B2O3 percentage
probably in relation with the apparition of liquid phase. For example, in the case of samples containing 30
% mol. in CT and sintered 1300°C, the addition of 1% mol. in B2O3 leads to an increasing in the relative
density from 65 to 93% and from 78 to 95% in the case 1350°C sintering temperature.
On the other hand, the obtained results reveal an increase in the relative density with sintering
temperature for all B2O3 percentage.
X-rays diffraction analyses carried out with different sintered samples showed the formation of
both BT and CT solid solutions, and a non identified phase. The proportion of the farmer phase increases
as a function of B2O3 addition.
Dielectric measurements carried out with samples containing 30% CT showed that the relative
permittivity (εr) increases as function of BO additions in the case of samples sintered at 1200°C. In the
case of higher sintering temperatures, maximum of permittivity is obtained with 1% BO. In addition, εr
evolution with the temperature reveals ferro para transformation in all considered samples.
In the second part, a new simple method was used, saving time and effort for the preparation of the
BCT. This method is the hydrothermal, a series of BCT samples were prepared without and with addition
of F2O3. We used in autoclave Ti metal plates with BaOH, CaO powders in addition to F2O3 Chloride
under temperature conditions of 200 ° C. for different periods of time. This allowed us to have the BCT
compound. Following the addition of Iron Chloride, we noticed a change in the structure approved by the
Raman, DRX and XPS analyzes. This latter confirms the presence of all the elements used in the synthesis
of the composit.
2017-07-03T00:00:00Z