98 bis boulevard Arago - 75014 Paris

From Cosmic Strings to CMB Observations


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).


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Thursday 24th March

9.30-10.00: S. White "Using gravitational lensing to recalibrate scaling relations for the gas content of dark matter halos" abstractBy stacking data for dark matter halos as a function of the stellar mass of their central galaxy it is possible to get high signal-to-noise measurements of their mass, X-ray and SZ profiles. This allows a direct calibration of the relations between halo mass and halo gas and galaxy content with relatively little model dependence and over a braod halo mass range.
10.00-10.30: B. Guiderdoni "The GalICS Semi-analytic Model of Galaxy Formation and VLT/MUSE: insights on the nature of z> 3 Lyman Alpha Emitters" abstractI will report on recent developments of the GalICS semi-analytic model of galaxy formation (originally Hatton et al. 2003, and subsequent papers) to elucidate the nature of high-redshift Lyman Alpha Emitters (LAE), in the context of the preparation and first observing runs of a deep extragalactic survey with VLT/MUSE (a powerful integral field spectrograph in operation at Paranal since 2014). LAE are identified by their Ly alpha resonant emission line whose modeling is complex. We have coupled GalICS with a Monte-Carlo Lyman alpha transfer code in order to be able to make predictions on a full set of statistical properties of LAE (Garel et al. 2012, 2015, 2016). We predict that Lyman alpha photons escape more easily from low-mass galaxies, and that many low-luminosity LAE at z=3 will be found by VLT/MUSE at fluxes of a few times 10-19 erg/s/cm2. The descendants of these low-luminosity LAE are now hosted by typical haloes comparable to those hosting the Milky Way. Some preliminary results of VLT/MUSE will be discussed in this context.
10.30-11.00: Coffee Break
11.00-11.30: D. Weinberg "Large Scale Structure: Past, Present, and Future" abstractI will describe how the field of large scale structure has evolved from the 1980s to today, and the opportunities and challenges for the coming 15 years. I will pay particular attention to the projects I know best: the Sloan Digital Sky Survey, the Dark Energy Survey, the Dark Energy Spectroscopic Instrument, and the WFIRST mission. The combination of CMB data, supernova measurements, and large scale structure traced by galaxies and the Lyman-alpha forest have led us to a well tested cosmological model with tightly constrained parameters, and to a good understanding of the relation between the dark matter distribution, galaxies, and the intergalactic medium. A near-term challenge, particularly for DES, is to sharpen measurements of matter clustering to one-percent precision (and accuracy!), comparable to current measurements of the cosmic expansion history. Projects like DESI, LSST, Euclid, and WFIRST seek a further order-of-magnitude gain in measurement precision, requiring corresponding gains in control of sytematic opportunities. These advances could confirm the current cosmological standard model, or they could reveal quantitatively subtle but physically profound discrepancies that will point the way to deeper understanding of the physics of the universe.
11.30-12.00: R. Durrer "Relativistic Cosmological N-body simulations" abstractDespite the fact that General Relativity has already celebrated its 100 birthday (not 60), most cosmological N-body simulations still use old-fashioned Newtonian gravity. This with good reasons as I shall explain. Nevertheless, if we want to go beyond LCDM and especially include relativistic forms of matter or dark energy, relativistic simulations can become necessary in the time of precision cosmology. I shall present the basics of our relativistic code which will be made publicly available and which is capable to handle relativistic fluctuations. I also present first results obtained using our code.
12.00-14.00: Lunch Break
14.00-14.30: J. Silk "The Limits of Cosmology"
14.30-15.00: V. Mukhanov "Inhomogeneous Dark Energy"
15.00-15.30: R. Schaeffer "Clustering in the Universe"
15.30-16.00: Coffee Break
16.00-16.30: M. Lachieze Rey "(No) time In Relativity and Cosmology" abstractI will examine the status of time and time related notions in Einsteinian theories of Relativity and in Relativistic Cosmology
19.30: Dinner at the Luxembourg Palace (Sénat)
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