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AbstractAbstract
[en] This is an introductory paper to theoretical and experimental gravitational wave research. In the first part, we give the precise mathematical description of a weak gravitational wave in the general framework of metric theories. Then we discuss the effect of these waves on material systems and the principle of the present detectors. The third part concerns the generation of gravitational radiations and reviews the possible astrophysical sources. Finally, we discuss the limitations and the state of the art of present detectors
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Journal Article
Journal
Annales de Physique (Paris); ISSN 0003-4169;
; v. 10(3); p. 201-218

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AbstractAbstract
[en] We study a one arm pendular Fabry-Perot interferometer with specifications corresponding to the two arms interferometers designed to detect gravitational radiation. We consider the non linearities originating from the radiation force and the effects of time delays due to the finite length of the arm. We derive the exact and the associated ''predictivised'' equations for the motion of the suspended mirror. We show that effects of time delays increase considerably the stability of the device when the optical relaxation time is of the order of the period of the pendulum, a case of relevance when light is recycled. However the thermal noise does not seem to be much modified when calculated within a simple approximation scheme
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Journal Article
Journal
Annales de Physique (Paris); ISSN 0003-4169;
; v. 10(3); p. 241-252

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AbstractAbstract
[en] A review is made on the results concerning the stellar populations in the central region of the galaxies
[fr]
Il est presente une revue des resultats obtenus sur les populations stellaires dans les regions centrales des galaxiesOriginal Title
Determination des populations stellaires dans les regions centrales des galaxies
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Journal Article
Journal
Annales de Physique (Paris); ISSN 0003-4169;
; v. 4(2); p. 147-149

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AbstractAbstract
[en] There is to-day a general agreement to consider General Relativity as the most efficient theory to describe the observational data in cosmology. In particular, Friedmann's Models offer good interpretation of the Hubble's Law and of the 30K cosmic radiation considered as the present residual energetic effect to the big bang. To-day cosmologists begin to study the energetic component of the universe, while, during the past years, only its material component was taken in account. The study of the early universe is now approaching the primeval explosion. At this knowledge level, the fondamental structures of our mind are reflected upon the object of their studies and there exists a parallel between the physical universe and the mathematical universe of the sets
[fr]
Actuellement la plupart des astrophysiciens s'accordent a reconnaitre que la theorie de la Relativite Generale reste celle qui regroupe le plus de faits observationnels relatifs a la cosmologie. Les modeles de Friedmann en particulier rendent bien compte de la loi de Hubble et de la loi du refroidissement energetique qui conduit aujourd'hui a l'observation d'un rayonnement cosmique de 30K. Apres etre restee longtemps l'etude de la seule composante materielle de l'univers, la cosmologie aborde aujourd'hui l'etude de sa composante energetique, remontant le passe de l'univers jusqu'a l'approche de son explosion primordiale. A ce niveau de connaissance, les structures de la raison se projettent sur leur objet et un parallele se dessine entre l'univers physique et l'univers mathematique des ensemblesOriginal Title
Bilan sur la cosmologie
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Journal Article
Journal
Annales de Physique (Paris); ISSN 0003-4169;
; v. 4(2); p. 209-212

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AbstractAbstract
[en] The basic ideas of the model microfield method are shortly reviewed. Recent applications to the broadening of the alkali metal resonance lines, of hydrogen lines and of overlapping helium lines are presented. Some approximations are discussed with special emphasis on the problem of the ion dynamics
[fr]
Les idees de base de la methode du microchamp modele sont brievement rappelees. Des applications recentes a l'elargissement des raies de resonance des metaux alcalins, de l'hydrogene et des raies d'helium a composante interdite sont presentees. On discute de quelques approximations en mettant particulierement l'accent sur le probleme de la dynamique des ionsOriginal Title
Methode du microchamp modele. Applications recentes a l'elargissement Stark des raies d'atomes neutres
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Source
Colloquium on the influence of the collisional processes on the spectral line profiles; Orleans, France; 4 - 5 Sep 1979
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Journal Article
Literature Type
Conference
Journal
Annales de Physique (Paris); ISSN 0003-4169;
; v. 5(4); p. 219-226

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AbstractAbstract
[en] The manner in which laser spectroscopic techniques can be use to probe collisional processes in atomic vapors is reviewed. A discussion of the saturation spectroscopy of three-level systems, coherent transient spectroscopy, and a beam-laser spectroscopy system is presented. It is shown that such experiments can provide useful information on both the total and differential cross sections for atom-atom scattering
Primary Subject
Source
Colloquium on the influence of the collisional processes on the spectral line profiles; Orleans, France; 4 - 5 Sep 1979
Record Type
Journal Article
Literature Type
Conference
Journal
Annales de Physique (Paris); ISSN 0003-4169;
; v. 5(4); p. 199-206

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AbstractAbstract
[en] A 21-cm line study of a sample of galaxies shows that in some of them, the gas extends far away from the optical limits. Some of these galaxies are isolated, as for example NGC 1744. On the contrary, NGC 520 and IC 5039 seem to suffer an interaction from a nearby companion
[fr]
L'etude en raie 21 cm d'un echantillon de galaxies montre que dans certaines d'entre elles le gaz s'etend a de tres grandes distances des limites optiques. Certaines de ces galaxies sont isolees, comme NGC 1744. Au contraire NGC 520 et IC 5039 semblent en interaction avec un compagnon voisinOriginal Title
Distribution de l'hydrogene neutre a grande distance du centre des galaxies
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Journal Article
Journal
Annales de Physique (Paris); ISSN 0003-4169;
; v. 4(2); p. 159-161

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AbstractAbstract
[en] With the improvements accomplished during the past 15 years in detection technics and instrumentation and with the opening of space exploration, molecular spectroscopy has become a very efficient way to probe planetary atmospheres
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Journal Article
Journal
Annales de Physique (Paris); ISSN 0003-4169;
; v. 9(4); p. 575-584

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AbstractAbstract
[en] During the past twenty years, considerable progress has been made in the production and in the use of synchrotron radiation. Nowadays, the advent of ultra-high vacuum toroidal grating monochromators coupled to modern storage rings has made possible a new class of sophisticated experiments whose development has gone hand in hand with the continuous improvements in the technology of synchrotron radiation. The simple example of photoionization processes in helium is taken to illustrate these parallel developments. The present status of experiment is summarized, with particular emphasis on recent measurements of very weak photoionization processes leaving the positive He+ ion in the n = 2 and n = 3 excited states. Further improvements are still expected from the use of ondulators mounted on new storage rings, which will offer spectacular possibilities to the experimental investigations, in particular in atomic physics
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Journal Article
Journal
Annales de Physique (Paris); ISSN 0003-4169;
; v. 7(4); p. 231-245

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AbstractAbstract
[en] In this paper, the principle of several methods of laser spectroscopy are reviewed in the perspective of application to thermal collision studies. Methods of linear-absorption, saturated-absorption and two-photon absorption are considered. It is shown how from the recording of line profiles, one can extract valuable data on various collisional processes that occur in vapors and discharges
[fr]
On presente dans cet expose le principe et les principales applications de quelques methodes de spectroscopie laser dont le but est l'etude des collisions aux energies thermiques. Ce sont essentiellement les methodes de spectroscopie d'absorption lineaire, d'absorption saturee, d'absorption a 2 photons. On montre comment, a partir de l'enregistrement des profils de raie, on peut extraire des informations sur les differents processus collisionnels qui se produisent dans les vapeurs et dechargesOriginal Title
Forme des raies en spectroscopie laser
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Source
Colloquium on the influence of the collisional processes on the spectral line profiles; Orleans, France; 4 - 5 Sep 1979
Record Type
Journal Article
Literature Type
Conference
Journal
Annales de Physique (Paris); ISSN 0003-4169;
; v. 5(4); p. 187-198

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