Conveners
Parallel Session 2: Cosmology & Astroparticle Physics
- There are no conveners in this block
Parallel Session 2: Cosmology & Astroparticle Physics
- There are no conveners in this block
Parallel Session 2: Cosmology & Astroparticle Physics
- Miguel Pato (TU Munich)
Parallel Session 2: Cosmology & Astroparticle Physics
- Mathias Garny (Desy)
Parallel Session 2: Cosmology & Astroparticle Physics
- Riccardo Catena (Institut fuer Theoretische Physik Goettingen)
Mr
Martin Vollmann
(PhD student), Dr
Masaki Asano
(Post-doc)
26/09/2012, 14:00
Cosmology & Astroparticle Physics
An analysis of the Fermi gamma ray space telescope data has recently revealed a resolved gamma-ray feature close to the galactic center which is consistent with monochromatic photons at an energy of about 130 GeV. If interpreted in terms of dark matter (DM) annihilating into gamma gamma (gamma Z,gamma H), this would correspond to a DM article mass of roughly 130 GeV (145 GeV, 155 GeV). The...
Mr
Sergio Lopez Gehler
(TU München)
26/09/2012, 14:20
Cosmology & Astroparticle Physics
The observation of a sharp spectral feature in the gamma-ray sky would be one of the cleanest ways to identify dark matter and pinpoint its properties. Over the years a lot of attention has been paid to two specific features, namely gamma-ray lines and internal bremsstrahlung. Here, we explore a third class of spectral signatures, box-shaped gamma-ray spectra, that naturally arise in dark...
Mr
Stefan Vogl
(TUM)
26/09/2012, 14:40
Cosmology & Astroparticle Physics
Over the last years both cosmic-ray antiproton measurements and direct dark matter searches have proved particularly effective in constraining the nature of dark matter candidates. The present work focusses on these two types of constraints in a minimal framework which features a Majorana fermion as the dark matter particle and a scalar that mediates the coupling to quarks. We derive...
Mr
Jonathan Da Silva
(LAPTh)
26/09/2012, 15:00
Cosmology & Astroparticle Physics
Searches for Dark Matter particles with indirect detection techniques have reached an important milestone with the measurements of the anti-proton and positron spectra by the PAMELA experiment and the gamma-ray fluxes by the FERMI-LAT experiment. While the γ-ray results have been used to test the thermal Dark Matter hypothesis and constrain the Dark Matter annihilation cross section into...
Mr
Sebastian Wild
(TU München)
26/09/2012, 15:50
Cosmology & Astroparticle Physics
The search for cosmic antideuterons has been proposed as a promising method to indirectly detect dark matter, due to the very small background flux from spallations expected at the energies relevant to experiments. The antideuteron flux from dark matter annihilation or decays is, however, severely constrained by the non-observation of an excess in the antiproton-to-proton fraction measured by...
Mr
Michael Duerr
(MPIK, Heidelberg)
26/09/2012, 16:10
Cosmology & Astroparticle Physics
Conversions and semi-annihilations of dark matter (DM) particles in addition to the standard DM annihilations are considered in a three-component DM system. We find that the relic abundance of DM can be very sensitive to these non-standard DM annihilation processes, which has been recently found for two-component DM systems. To consider a concrete model of a three-component DM system, we...
Dr
Anton Baushev
(DESY Zeuthen)
26/09/2012, 16:30
Cosmology & Astroparticle Physics
We consider the density profile of the central region of dark matter haloes. It turns out that under very general conditions the profile is universal: it depends almost not at all on the properties of the initial perturbation and is very akin, but not identical, to the Einasto profile.
We estimate the size of the 'central core' of the distribution, i.e., the extent of the very central...
Miguel Pato
(TU Munich)
26/09/2012, 16:50
Cosmology & Astroparticle Physics
Dark matter searches are entering a particularly exciting phase where the complementarity between different signals may finally be explored. This situation calls for a more accurate description of the dark matter distribution in our Galaxy. In this context, I will show that gravitational microlensing and dynamical observables can be combined to set interesting constraints on the dark matter...
Mr
Tibor Frossard
(Max-Planck-Institut für Kernphysik Heidelberg)
27/09/2012, 14:00
Cosmology & Astroparticle Physics
The observed baryon asymmetry of the Universe can be elegantly explained in the leptogenesis scenario, where a net lepton asymmetry produced by the decay of heavy right-handed neutrinos is then transfered to the baryon number through the Standard Model sphalerons.
Being an intrinsicly quantum effect the generation of such an asymmetry in the hot early Universe can be described...
Mr
Mathias Garny
(Desy)
27/09/2012, 14:20
Cosmology & Astroparticle Physics
Leptogenesis is an attractive mechanism for explaining the baryon asymmetry of the universe, and provides interesting links between cosmology and neutrino physics. In addition, within the scenario of resonant leptogenesis, models with implications for LHC and future colliders have been proposed. However, the predictions depend on a correct calculation of the generated asymmetry in terms of the...
Kai Schmitz
(DESY)
27/09/2012, 14:40
Cosmology & Astroparticle Physics
The spontaneous breaking of B-L symmetry naturally accounts for the small observed neutrino masses via the seesaw mechanism. We have recently shown that the cosmological realization of B-L breaking in a supersymmetric theory can successfully generate the initial conditions of the hot early universe, i.e. entropy, baryon asymmetry and dark matter, if the gravitino is the lightest superparticle...
Dr
Peihong GU
(Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany)
27/09/2012, 15:00
Cosmology & Astroparticle Physics
In this talk I will introduce a unified picture of Dirac neutrino masses,
baryon asymmetry and dark matter relic density. Specifically, we consider
an $SU(3)'_c\times SU(2)'_L\times U(1)'_Y$ dark
sector, parallel to the $SU(3)_c\times SU(2)_L\times
U(1)_Y$ ordinary sector. The hypercharges, baryon numbers and
lepton numbers in the dark sector are opposite to those in the
ordinary sector....
Dr
Riccardo Catena
(Institut fuer Theoretische Physik Goettingen)
27/09/2012, 15:50
Cosmology & Astroparticle Physics
In standard cosmology the present ratio of the dark matter (DM) and baryon energy densities is set by two completely unrelated mechanisms: the DM production mechanism and baryogenesis. Therefore, the fact that the observed value for this ratio is close to one may appear as a puzzling coincidence.
A scalar field interacting differently with DM and baryons
can explain dynamically why the ratio...
Dr
ARUNANSU SIL
(Indian Institute of Technology, Guwahati, INDIA)
27/09/2012, 16:10
Cosmology & Astroparticle Physics
We consider a smooth hybrid inflation scenario based on
a supersymmetric SU(2)_L x SU(2)_R x U(1)_(B-L) model.
The Higgs triplets involved in the model play a key role
in inflation as well as in explaining the observed baryon
asymmetry of the universe. We show that the baryon asymmetry
can originate via non-thermal triplet leptogenesis from
the decay of SU(2)_(B−L) triplets, whose...
Valerie Domcke
(DESY)
27/09/2012, 16:30
Cosmology & Astroparticle Physics
In superconformal D-term inflation, dangerous supergravity corrections to the scalar potential are controlled by a superconformal symmetry of the matter sector of the Lagrangian, a concept which has received recent interest in the context of Higgs inflation. Working out this idea in the context of D-term inflation, we find an interesting phenomology, in particular a two-field inflationary...
Mr
Markus Rummel
(University of Hamburg)
27/09/2012, 16:50
Cosmology & Astroparticle Physics
We discuss observational degeneracy between non-canonical and canonical single field inflation. We map the dynamics of the non-canonical inflationary trajectory to a Lagrangian with canonically normalized kinetic term and a scalar potential. At the level of the two-point function, the two theories are observationally degenerate at all times. To obtain observationally degeneracy at the level of...
Dr
Dominika Konikowska
(Bielefeld University)
27/09/2012, 17:40
Cosmology & Astroparticle Physics
We study a theory of dilaton gravity in a 5D brane scenario, with dilaton non-minimally coupled to the matter content of the universe localized on the brane. We investigate whether the observed large-scale structure of the universe can exist on the brane in the effective 4D dilaton gravity scenario with an exact anti de Sitter bulk. The corresponding constraint on the spatial derivative of the...
Dr
Rose Lerner
(Helsinki University)
27/09/2012, 18:00
Cosmology & Astroparticle Physics
We consider the possibility that the primordial curvature perturbation was generated through the curvaton mechanism from a scalar field with an electric charge, or precisely the Standard Model U(1) weak hypercharge. This links the dynamics of the very early universe concretely to the Standard Model of particle physics, and because the coupling strength is known, it reduces the number of free...
Dr
Jasper Hasenkamp
(Hamburg U.)
27/09/2012, 18:20
Cosmology & Astroparticle Physics
Current CMB observations could confirm an increase of the effective neutrino degrees of freedom at photon decoupling. We show that, if the gravitino problem is solved by a light axino, dark (decoupled) radiation emerges naturally after nucleosynthesis but before CMB times leading to a new upper bound on the reheating temperature < 10^10 GeV. In turn, successful thermal leptogenesis predicts...
Mr
Peter Graf
(Max-Planck-Institut fuer Physik)
27/09/2012, 18:40
Cosmology & Astroparticle Physics
We calculate the rate for thermal production of axions and saxions via scattering of quarks, gluons, squarks, and gluinos in the primordial supersymmetric plasma. Systematic field theoretical methods such as hard thermal loop resummation are applied to obtain a finite result in a gauge-invariant way that is consistent to leading order in the strong gauge coupling. We calculate the thermally...
