Statut  Confirmé 
Série  APCTH 
Domaines  hepth 
Date  Mardi 25 Avril 2017 
Heure  14:00 
Institut  APC 
Salle  646 A  Mondrian 
Nom de l'orateur  Chowdhury 
Prenom de l'orateur  Debika 
Addresse email de l'orateur  
Institution de l'orateur  Department of Physics, Indian Institute of Technology Madras, Chennai, India 
Titre  Behavior of threepoint functions in inflationary and bouncing scenarios 
Résumé  Inflation has been widely regarded as the most promising scenario to explain our observations of the early universe. However, in view of the difficulties associated with arriving at a unique model of inflation, it seems worthwhile to investigate alternative scenarios of the early universe, specifically the socalled bouncing models. In this talk, I shall discuss the evaluation of threepoint functions in a specific inflationary model and a particular class of bouncing models in order to illustrate the primary differences that can arise between these two scenarios at the level of the threepoint functions. I shall consider the axion monodromy model of inflation, which involves a canonical scalar field that is governed by a linear potential with superimposed modulations. I shall discuss the evaluation of the scalarscalartensor crosscorrelation in this model and analytically establish the consistency relation (in the squeezed limit) for this threepoint function. I shall then consider a specific class of bouncing models, namely the matter bounce scenario, and discuss the analytical evaluation of the tensor modes and the tensor bispectrum in this scenario. Further, I shall show that the consistency relation corresponding to the tensor bispectrum is violated in the matter bounce. The behavior of the nonGaussianities, specifically the threepoint functions, generated in the inflationary and bouncing scenarios can hence be used to compare and contrast between the predictions of these alternative models of the early universe. 
Numéro de preprint arXiv  
Commentaires  
Fichiers attachés 
Pour obtenir l' affiche de ce séminaire : [ Postscript  PDF ]

[ English version ] 