Nov 29 – 30, 2023
Europe/Paris timezone

With the advent of "precision cosmology", a number of anomalies of diverse statistical significance has emerged. These include, but are not limited to: the "Hubble tension" between measurements of the Hubble parameter with a variety of late-universe probes (cepheid-calibrated supernovae in particular) and its prediction from the LCDM model fit to early-universe data (Planck CMB data in particular); the "S8 tension" between the amplitude of the clustering measured via weak-lensing surveys and that predicted by the Planck/LCDM cosmology; a recent "growth factor" tension which reminds of the S8 tension; as well as older long-standing "cosmic dipole" anomalies, the famous "lithium problem", and even some intriguing anomalies within Planck data. As of yet, it is not clear whether these anomalies are connected to each other, or even that they are cosmological in origins. The workshop “anomalies in cosmology” aims to gather the efforts of cosmologists interested in these growing (potential) issues of the LCDM model, in order to foster works to better characterize what sorts of systematic effects could be at play, or conversely, what sorts of new physics would be responsible for these anomalies. This will also serve as a platform to discuss with astrophysicists and particle physicists interested in these topics, whose expertise could help the cosmology community in understanding the origin of these anomalies.


Focus of the first workshop:
The workshop "anomalies in cosmology" is organized in the context of the corresponding "transverse task force" of the GDR CoPhy.

The first meeting will take place on November 29th and 30th, and will be hosted by LAPTh, in Annecy-le-Vieux. It will focus on "cepheids'',  a key part of the distance ladder. The program includes:

-- A review of the Hubble constant measurement by SH0ES

-- A review of cepheids for cosmology

-- A review of potential systematics with cepheids/SN1a

-- A review of the TRGB calibration

-- Many discussions around the present and future of "cepheid cosmology"



Invited speakers:

-- Richard Anderson (EPFL Lausanne)

-- Pierre Kervella (Obs. de Meudon)

-- Pierre Astier (LPNHE)


Organizing committee:
Alain Blanchard, Vivian Poulin, Mickaël Rigault, Pasquale Serpico


The meeting is funded by the GdR CoPhy.

petit amphitéatre
LAPTH Annecy-le-vieux