November 21, 2013

Note that this meeting will be on THURSDAY!

We will have talks by Nassim Bozorgnia (MPI Heidelberg) and Fabio Iocco (IFT) about their research on DM direct detection and DM constraints from CMB observations, respectively.

Nassim Bozorgnia (MPI Heidelberg)
Title: Analysis of direct dark matter detection data in a halo independent way

Abstract:
The dark matter velocity distribution which is used in the analysis of data from direct dark matter detection experiments is not very well known. This results in significant uncertainty in interpreting direct detection data. I will present astrophysics independent methods to analyze the results of dark matter direct detection experiments. In particular, the dependence on the dark matter halo can be integrated out by expanding the rate in the Earth's velocity. I will discuss the conditions that the dark matter halo should fulfill so that the expansion is be well-behaved and halo independent bounds can be safely applied.

October 2, 2013

Please let me know if you'd like to give a short talk or present a recent paper, specially in trendy topics as warm DM and/or low mass DM.  

Germán Gómez-Vargas (UAM-IFT) will share some novel ideas on DM indirect detection presented in the anisotropic universe workshop held in Amsterdam.

 

September 18, 2013

 We are skipping the bi-weakly agreement due to the many activities in the IFT the following weeks. We will discuss the three WIMP events claimed by the CDMS collaboration here, and also we will have  Dr. Bryan Zaldivar (IFT) talking about his most recent work:


"The largest temperature of the Universe, and the Gravitino abundance"

abstract:

The evolution of the thermal plasma from the end of inflation to the end of reheating epoch is discussed. On the other hand, bounds on the inflaton parameters are obtained from kinematical criteria concerning the inflaton decay products, and, as an example, the consequences on gravitino abundance are discussed. 

 

September 11, 2013

 

We are starting up the dark matter meetings again after our August break. On the agenda we have:

--- Csaba Balazs (Monash Universitys, Melbourne) will discuss the positron excess

--- German Gomez-Vargas (UAM - IFT): New AMS02 results, DM or pulsars?

June 19, 2013

The dependence of dark matter profiles on the stellar to halo mass ratio: a prediction for cusps vs cores

Arianna di Cintio (UAM)

Abstract:

 We use 31 simulated galaxies from the MaGICC project to investigate the effects of baryonic feedback on the density profiles of dark matter (DM) haloes. The sample covers a wide mass range: 9.4e9<Mhalo/Msun<7.8e11, hosting
galaxies with stellar masses: 5.0e5<M*/Msun<8.3e10, i.e. from dwarf to L*. The galaxies are simulated with several baryonic prescriptions, including a range of stellar feedbacks. The main result is a clear dependence of the inner slope
of the DM density profile, \alpha\ in \rho~r^\alpha, on the ratio between stellar-to-halo mass (M*/Mhalo). This relation is independent of the stellar feedback scheme, allowing a prediction for cusp vs core formation. When M*/Mhalo is low, ~0.01%, energy from stellar feedback is insufficient to significantly alter the inner DM density and the galaxy retains a cuspy profile. At higher M*/Mhalo, feedback drives the expansion of the DM and generates cored profiles. The flattest profiles form where M*/Mhalo~0.5%. Above this ratio, stars formed in the central regions deepen the gravitational
potential enough to oppose this supernova-driven expansion process, resulting in smaller cores and cuspier profiles. Combining the dependence of \alpha\ on M*/Mhalo with the abundance matching relation between M* and Mhalo provides a prediction for how \alpha\ varies with M*. Further, using the Tully-Fisher relation allows a prediction for the dependence of the DM inner slope on the observed rotation velocity of galaxies. The most cored galaxies are expected to have Vrot~50km/s, with \alpha\ decreasing for more massive disc galaxies: spirals with Vrot~150km/s have central slopes \alpha<-0.8, approaching the NFW profile. This novel prediction for the dependence of \alpha\ on disc galaxy
mass can be tested using current observational data sets, and can be applied to theoretical modeling of mass profiles and populations of disc galaxies. 

 

June 5, 2013

The Fermi-LAT Collaboration has posted in arXiv a paper on line searches paying special attention to the 130 GeV claim, let's take some minutes to discuss about it http://arxiv.org/abs/1305.5597.

We also have Edoardo Carlesi from UAM talking about interactions in the dark universe.

ABSTRACT: In this short seminar I plan to discuss how we can use cosmological N-body / SPH simulations to constrain cosmological models beyond LambdaCDM. I will introduce the results of a series of high-resolution hydrodynamical simulations of models where dark matter feels an additional, dark-energy
mediated force, and identify the observational signatures of such coupling. In particular, I will discuss predictions for large scale structures, galaxy clusters, structure of the cosmic web and the properties of dark matter halos.

 

May 8, 2013

Please bring your favorite DM paper to have a small discussion, also if you want to lead a discussion on a hot DM topic you are more than welcome! We will start with this paper http://arxiv.org/abs/1305.0830 

 

April 10, 2013

This meeting will be direct detection devoted.  We will have Miguel Peiró talking about Direct Detection and complementarity among different targets, and Elias Lopez giving a talk about Direct searches with CDMS. Elias  is postdoc in the IFT and member of the CDMS collaboration, so come prepared to Everything you always wanted to know about CDMS * But were afraid to ask. If you are not an expert on direct searches, don't panic! Miguel will give an intro. 

 

February 27, 2013

For this Wednesday meeting we will have two DM papers born in the IFT! Please take a look: "Milli-Charged Dark Matter in Quantum Gravity and String Theory" Pablo Soler (Madison & Hong Kong) et. al. arXiv:1302.5471 and "Gauge Coupling Unification and Non-Thermal Dark Matter" Bryan Zaldivar (IFT) et.al. arXiv:1302.4438.

In the second part of the meeting Yago Ascasibar (UAM) will present his research. Slides

 

February 13, 2013

For the next DM IFT/UAM meeting we will have shot gun talks!!

We'd like to ask students/postdocts to volunteer themselves for presenting their research (it doesn't exclude seniors).

Other that that, please let me know if you are interested in given a 20 min talk.

For those of you that haven't attended one of the meetings yet, first: you are very welcome, and let me know about shotgun talks, you are limited to **max 3 slides and min 1 slide**. You'll have 5 min to talk, 3 min for questions. You can talk about work in progress: your job is to peak our interest, not give us a DM review.

Germán Gómez-Vargas and Carlos Muñoz slides

Michael Grefe slides

 

January 30, 2013

In our second meeting there will be 20 min for short personal/group presentations, who's who and what we are doing in the wonderful dark matter world. Also, we'll have a 30 min. presentation by Bryan Zaldivar on his research: what synchroton and colliders can tell us on DM, and a work-in-progress on non-thermal genesis of DM, slides.

 

January 16, 2013

For the first meeting Germán Gómez-Vargas will do a brief introduction to dark matter indirect searches and present a work-in-progress on testing dark matter models with Fermi-LAT observations of the center of our galaxy. Slides