CCAPP Cosmology Lunch meets on Thursdays at 12:30 pm in the Price Place (PRB M2005).

Jun 25, 2015

June 11, 2015

June 4, 2015
May 28, 2015 

May 13, 2015, 

May 7, 2015, 

April 30, 2015, 

    

April 23, 2015,

April 16, 2015, 


April 9, 2015, 
  • Guest talk by Evan Scheider
    • Introducing CHOLLA: A New Massively-Parallel Hydrodynamics Code
    • In recent years, computer architectures have grown to incorporate a variety of accelerators that substantially increase the power of a CPU by providing access to thousands of parallel computational elements. Among these accelerators are graphics processor units, or GPUs - devices that were originally designed for on-screen pixel rendering but have since been adapted for general use by the scientific community. In this talk, I will give an overview of a new massively-parallel hydrodynamics code, CHOLLA, written to run natively on these devices. I will discuss advantages and limitations of the GPU programming model, and show some initial scientific results obtained with CHOLLA on the El Gato cluster at the UofA
  • Talk by Ashely Ross
    • Early Dark Energy Survey Science Results.  

April 2, 2015, 

March 26, 2015, 

March 19, 2015 

March 12, 2015

March 5, 2015 

Feb 26, 2015

Feb 19, 2015
    
    

Feb 12, 2015
Feb 5, 2015 

Jan 29, 2015 

Jan 22, 2015 

Jan 15, 2015 


Dec 18, 2014
    
  •     Slepian and Eisenstein 2014, http://arxiv.org/pdf/1411.4052v1.pdf, "On the signature of the baryon-dark matter relative velocity in the two and three-point galaxy correlation functions"

Dec 11, 2014
    Guest talk by Alice Pisani. 
        Precision Cosmology with Cosmic Voids: 
            Modern surveys allow us to access to high quality measurements, by sampling the galaxy distribution in detail also in the emptier regions, voids. Cosmic voids present  themselves as a new tool to constrain cosmology. While the treatment of systematics is simpler in these empty regions, with the aim of achieving the level of precision cosmology a careful modeling of such effects is necessary.  In particular, peculiar velocities affect the way we observe cosmic voids, and thus their effect needs to be understood. Using mock catalogues, I analyze the effect of  peculiar velocities on void properties.  In this talk I thus present the results of the analysis of the                 systematic effects affecting voids and discuss it in the framework of current and future surveys. Additionally, I present a preliminary forecast for void abundances with the   future Euclid and Wfirst missions and obtain, using the Fisher matrix formalism, a prediction for the constraints that void abundances will set on cosmological parameters.

Dec 4, 2014
Nov 20, 2014

Nov 13, 2014

Nov 6, 2014

Oct 30, 2014
  • Chevallard et al. 2014, http://arxiv.org/pdf/1410.7768.pdf, "Effect of primordial non-Gaussianities on the far UV-luminosity function of high-redshift galaxies: implications for cosmic reionization"
  • Ngolè Mboula et al., http://arxiv.org/pdf/1410.7679.pdf, "Super-resolution method using sparse regularization for point-spread function recovery"
  • Thompson et al., http://arxiv.org/abs/1410.7438, "The rise and fall of a challenger: the Bullet Cluster in Lambda Cold Dark Matter simulations"

Oct 23 2014, 
   
    Talk by Andreu Font-Ribera (Lawrence Berkeley National Laboratory): "Studying the Expansion of the Universe with BOSS quasars"
            After six years of observations, the Baryon Oscillation Spectroscopic Survey (BOSS) ended last summer, and will soon make its data public
            (SDSS Data Release 12). During these years, it has used the SDSS telescope to obtain spectra of 1.5 million galaxies to get very
            accurate measurements of the Baryon Acoustic Oscillations (BAO) scale at redshift z ~0.5. At the same time, BOSS observed over 184 000 high
            redshift quasars (z>2.15) with the goal of detecting the BAO feature in the clustering of the intergalactic medium, using a technique known
            as the Lyman alpha forest (LyaF).
            In this talk I will overview several results from the LyaF working group in BOSS, including the measurement of BAO at z=2.4 both from the
            auto-correlation of the LyaF (Delubac et al. 2014), and from its cross-correlation with quasars (Font-Ribera et al. 2014). From the
            combination of these studies we are able to measure the expansion rate of the Universe 11 billion years ago with a 2% uncertainty.

Oct 16, 2014

Oct 9, 2014 
    

Oct 2, 2014 

Sept 25, 2014 

Sept 18, 2014

Sept 11, 2014
    

Sept 4, 2014 


August 28, 2014
August 21, 2014