98 bis boulevard Arago - 75014 Paris

From Cosmic Strings to CMB Observations

NEWS

Welcome cocktail

A welcome cocktail will take place on Wednesday, 23rd from 5.30 pm to 8.00 pm at IAP.

 

Conference dinner

The dinner will take place on Thursday, March 24th (7.30 pm, smart dress code) at the Luxembourg Palace (Sénat).

Program



Wednesday 23th March

13.30-14.00: J. Martin "Introduction"
 
14.00-14.30: D. Bennett "Simulations of Cosmic Strings in the Early Universe and Conflict with the Dreaded Turok" abstractIn 1986, as I was just finishing my thesis on an analytic model of cosmic string evolution, I traveled from Stanford to the Lawrence Livermore National Laboratory to meet Francois Bouchet and George Fuller, who were just embarking on writing a cosmic string simulation code. Inspired by the amazing ability of cosmic string loops to explain the Abell Cluster correlation function, Francois and George wanted to study cosmic string seeded galaxy formation. I invited myself to join their collaboration, and Fuller soon dropped out. Francois and I spent the next 6 years in close collaboration as we worked out the true evolution of cosmic strings in the early universe, discovered the secret of the matching correlation function of cosmic string loops and the Abell Cluster correlation function, and discovered (with the help of the COBE-DMR CMBR anisotropy measurements) that cosmic strings could not provide sufficient perturbations to seed the observed distribution of galaxies. It was a great pleasure to work with Francois for all those years, and I learned a lot from the experience. I learned how to and how not to build a robust simulation code, and why one should not accept a postdoc from one's main rival. My collaboration with Francois also led directly (and entirely by accident) to the creation of the field of observational gravitational microlensing.
 
14.30-15.00: C. Ringeval "CSMB: The Cosmic String Microwave Background"
 
15.00-15.30: A. Ducout "Minkowski Functionals and non Gaussianity in the CMB" abstractMinkowski Functionals are a set of morphological tools used to perform statistical analyses of random fields. They have been used in particular to assess the Gaussianity of the Cosmic Microwave Background as they are sensitive to every order of non Gaussianity. I will review the different models they were able to constrain, in particular primordial non Gaussianity (inflation, cosmic strings) but also astrophysical signals (Galactic residuals or lensing of the CMB by large scale structures). Finally I will show how they compare to other estimators, the results obtained with the Planck mission and the prospects for future missions, in both temperature and polarisation.
 
15.30-16.00: Coffee break
 
16.00-16.30: E. Bertschinger "The Influence of Dynamical Francois" abstractStarting with his PhD thesis, Francois Bouchet has made major contributions to our understanding of the gravitational dynamics of large scale structure. I will review his analytical and numerical approaches to nonlinear clustering which deeply influenced me and others in the field.
 
16.30-17.00: O. Doré "SPHEREx: An all sky spectral survey (via Skype)" abstractSPHEREx, a mission in NASA's Small Explorer (SMEX) program that was selected for Phase A in July 2015, is an all-sky survey satellite designed to address all three science goals in NASA’s astrophysics division: probe the origin and destiny of our Universe; explore whether planets around other stars could harbor life; and explore the origin and evolution of galaxies. These themes are addressed by a single survey, with a single instrument. In this talk, we describe how SPHEREx can probe the physics of inflationary non-Gaussianity by measuring large-scale structure with galaxy redshifts over a large cosmological volume at low redshifts, complementing high-redshift surveys optimized to constrain dark energy. There is nothing like a new multicolor space mission to honor a colorful and volcanic PhD advisor.
 
17.00-17.30: F. Bernardeau "Large-deviation functions in the large-scale structure cosmology" abstractThe existence of large deviation functions (LDF) is ubiquitous in many fields of applied mathematics and statistical mechanics such as basic random processes, equilibrium many body systems or even nonequilibrium, disordered and chaotic systems. Following pioneering results obtained by François and his collaborators 2 decades ago, I present here results that show that such LDFs can be built in the context of the evolution of the large-scale structure of the universe.
 
17.30-20.00: Cocktail
 
UMR7095 - Institut d'Astrophysique de Paris - 98 bis boulevard Arago - 75014 Paris - Phone 33 (1) 44 32 80 00 - Fax 33 (1) 44 32 80 01