Test des modèles d'énergie noire et propriétés physiques des amas de galaxies

Les amas de galaxies sont les objets les plus massifs de l'Univers. Leur population étant directement liée au taux de croissance des perturbations de matière, l'évolution de leur abondance dans le temps permet de poser des contraintes sur l'évolution de l'Univers. La découverte d'un rayonnement X dans ces objets a permis de mettre en évidence les propriétés du gaz intra-amas ainsi que les différents processus responsable de l'émission X. Grâce à la capacité de spectro-imagerie haute résolution des instruments de dernière génération comme XMM-Newton ou Chandra, les observations ont permis de mieux comprendre l'évolution des amas de galaxies et d'utiliser leur abondance comme un test cosmologique. L'étude statistique optimale de cette population nécessite une bonne détermination de la masse des amas. Cette quantité n'étant cependant pas mesurable directement, des méthodes indirectes ont été développées notamment en utilisant des relations d'échelle ce qui permet de relier la masse aux propriétés du gaz intra-amas. Cependant la physique de ce gaz peut engendrer des biais dans la détermination de la masse qui se répercutent sur la détermination des paramètres cosmologiques. Cette thèse présente une étude du gaz intra-amas à travers la relation d'échelle masse-température à partir des contraintes obtenues grâce à différentes sondes cosmologiques ainsi que la distribution en température des amas X. Avec la publication des futurs résultats des expériences Planck, South Pole Telescope ou bien Atacama Cosmology Telescope, une prédiction de la population des amas observés par effet Sunyaev-Zel'dovich est détaillée en prenant en compte les propriétés X du gaz intra-amas de façon auto-consistante. Enfin, une étude qualitative du spectre de puissance des anisotropies secondaires du CMB induites par l'effet SZ est proposée afin de montrer les différences observées dans le spectre en prenant en comptes les propriétés du gaz des amas.Galaxy clusters are the most massive objects in the Universe. Their population being directly linked to the growth factor of the matter density fluctuations, the evolution of the abundance is a good test to place constraints on the evolution of the Universe. The discovery of an X-ray radiation inside these objects allowed us to highlight the properties of the intra-cluster gas as well as the different process responsible of the X-ray emission. Thanks to the capacity of spectro-imagery of XMM-Newton or Chandra, the observations allowed us to better understand the clusters evolution and to use their abundance as cosmological test. The statistical study of this population needs a good determination of the clusters' mass. This quantity being not directly measurable, indirect methods had been developed notably using scaling relation allowing to link the clusters' mass to the properties of the intra-cluster gas. However, a bad understanding of the gas physics can lead to systematics that could insert some bias in the determination of the cosmological paramters. This thesis deals with a study of the intra-cluster gas through the scaling relation between the mass and the temperature using the constraints taken from cosmological probes and the temperature distribution of X-ray clusters. With the forthcoming publications of result from Plank, South Pole Telescope or Atacama Cosmology Telescope, a prediction of the clusters population observed by Sunyaev-Zel'dovich effect is detailed by taking into account the X-ray intracluter gas properties. Finally, a quantitative study of the power spectrum of the secondary anisotropies of the CMB induced by SZ effect is proposed in order to show the differences observed in the spectrum taking into account the clusters' gas properties

Deploying the ATLAS Metadata Interface (AMI) stack in a Docker Compose or Kubernetes environment

ATLAS Metadata Interface (AMI) is a generic ecosystem for metadata aggregation, transformation and cataloging. This paper describes how a renewed architecture and integration with modern technologies ease the usage and deployment of a complete AMI stack. It describes how to deploy AMI in a Docker Compose or Kubernetes environment, with a particular emphasis on the registration of existing databases, the addition of more metadata sources, and the generation of high level Web search interfaces using dedicated wizards

Using MQTT and Node-RED to monitor the ATLAS Meta-data Interface (AMI) stack and define metadata aggregation tasks in a pipelined way

ATLAS Metadata Interface (AMI) is a generic ecosystem for metadata aggregation, transformation and cataloging. Each sub-system of the stack has recently been improved in order to acquire messaging/telemetry capabilities. This paper describes the whole stack monitoring with the Message Queuing Telemetry Transport (MQTT) protocol and Node-RED, a tool for wiring together hardware/software devices. Finally, this paper shows how Node-RED is used to graphically define metadata aggregation tasks, in a pipelined way, without introducing any single point of failure

Search for the lepton flavor violating decay A^0/H^0 --> tau^{+/-} mu^{+/-} at hadron colliders

In the two Higgs doublet model type III and in several other extensions of the Standard Model, there are no discrete symmetries that suppress flavor changing couplings at tree level. The experimental observation of the nu_mu -- nu_tau flavor oscillation may suggest the non-conservation of lepton number. This would lead to the decay of the type A^0/H^0 --> tau^{+/-} mu^{+/-}. We determine the present low energy limit on lepton flavor violating (LFV) couplings from the muon g-2 measurement and discuss the prospects for detecting lepton flavor violating decays at the TeVatron and at the Large Hadron Collider. The achievable bounds on the LFV coupling parameter lambda_{tau mu} are presented.Comment: 19 pages, 21 figures. Updated version takes into account the recent results on the muon g-2 measurements. Submitted to Phys. Rev. D. Added minor corrections from a refere

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements