Conveners
10 - Cosmic magnetic fields: Probes
- Tina Kahniashvili
10 - Cosmic magnetic fields: Probes
- Tina Kahniashvili
10 - Cosmic magnetic fields: Origin, evolution and signatures
- Tina Kahniashvili
10 - Cosmic magnetic fields: origin, evolution and signatures
- Tina Kahniashvili
Prof.
Philipp Kronberg
(University of Toronto)
06/12/2015, 14:00
Talk
In this talk I focus on magnetic probes and related discoveries of the physical state of space between stars and galaxies. It begins with the Milky Way disc, then clusters of galaxies, magnetic fields in the megaparsec scale filaments of Large Scale Structure (LSS), and cosmological voids. I discuss the energetics, some the physical, and gas dyamical basics, and the measurement techniques used...
PAOLO DA VELA
(INFN - National Institute for Nuclear Physics)
06/12/2015, 14:45
Talk
The origin of cosmic magnetic fields permeating galaxies and clusters is still unknown.To undertstand the origin and the evolution of the primordial cosmic magnetic fields we need to probe the existence and to characterize magnitude and correlation length of magnetic field in voids (Intergalactic magnetic field, IGMF), where pollution from magnetic fields associated to structures is expected...
Prof.
Reinhard Schlickeiser
(Ruhr University Bochum, Germany)
06/12/2015, 15:05
Talk
Two recent estimates of lower limits for the stochastic primordial magnetic fields are reviewed. The first estimate pioneered by Neronov and Vovk (2010) is based on GeV-TeV $\gamma $-ray observations of distant blazars by air-Cherenkov telecopes and the FERMI satellite. The generated $e^{\pm }$ pair beams from double photon collisions with the extragalactic background light have been expected...
Daniela Paoletti
(INAF and INFN)
06/12/2015, 16:15
Talk
Primordial magnetic fields (PMF) may represent the "progenitors"
of the fields we observe in large scale structures and their
study could open a new observational window on the early universe. The
Cosmic Microwave Background, thanks to its different probes,
represents one of the best laboratory to investigate and constrain the
nature of PMF. I will present the Planck 2015 constraints on...
Dr
Kerstin Kunze
(University of Salamanca)
06/12/2015, 16:35
Talk
The presence of large scale magnetic fields at different epochs can be probed by their impact on different observables such as the CMB spectrum, primary and secondary CMB anisotropies, matter power spectrum and 21cm line emission. I will give an overview of these effects together with constraints from current and future experiments.
Dr
Levon Pogosian
(Simon Fraser University)
06/12/2015, 16:55
Talk
I will discuss CMB signatures of primordial magnetic fields, some of the existing constraints, and what can be expected from future CMB experiments.
Hector Javier Hortua
(Universidad Nacional)
06/12/2015, 17:15
Poster
In this work we compute the temperature-polarization correlations
(C_l^(TB) and C_l^(EB)) in the cosmic microwave background (CMB) generated by the presence of causal primordial magnetic fields with a helical contribution.
We analize the effect of an infrared cutoff in the power spectrum of causal fields on the cross-correlation and we compare our result with previous work.
Christos Tsagas
(Aristotle University of Thessaloniki)
07/12/2015, 14:00
Talk
Inflation has long been thought as the best way of producing large-scale primordial magnetic fields. To achieve fields strong enough to seed the galactic dynamo, most of the generation mechanisms operate outside conventional electromagnetic theory, which is typically restored after the end of the de Sitter phase. Breaking away from standard electromagnetism can lead to substantially stronger...
Dr
Alexey Boyarsky
(Leiden University (NL)),
Oleg Ruchayskiy
(Ecole Polytechnique Federale de Lausanne (CH))
07/12/2015, 14:21
Talk
If chiral (left-right) asymmetry is present in the plasma,
the electric current, parallel to the magnetic field, appears. This is known as
"*chiral magnetic effect*". We demonstrate that this effect changes the dynamics of the magnetized relativistic plasma and present the proper equations of chiral relativistic magnetohydrodynamics, containing a new, axion-like, degree of freedom. There...
Axel Brandenburg
(Nordita)
07/12/2015, 15:03
Talk
There was a time when primordial magnetic fields posed a serious
contender to explaining the origin of magnetic fields in galaxies
and on larger scales. This has changed drastically during the past
three decades, and now the dynamo origin of galactic magnetic fields is
unchallenged. Nevertheless, primordial magnetic fields might still be an
attractive possibility to explaining magnetic...
Andrey Beresnyak
(Naval Research Laboratory)
07/12/2015, 15:24
Talk
MHD Turbulence is a strongly nonlinear dynamics of conductive fluids, e.g. plasma. Recent progress in theory regarding almost all basic regimes of this dynamics -- from how the magnetic field is generated (dynamo problem), to how turbulence is decaying, to what are the asymptotic scaling laws, allowed us to proceed with more observationally motivated questions. One of them is why almost all...
Dr
Andrey Saveliev
(University of Hamburg/Keldysh Institute)
07/12/2015, 16:15
Talk
In order to give a consistent picture of cosmic, i.e. galactic and extragalactic, magnetic fields, different approaches are possible and often even necessary. Here we present three of them: First, a semianalytic analysis of the time evolution of primordial magnetic fields from which their properties and, subsequently, the nature of present-day intergalactic magnetic fields may be deduced....
Dr
Francesco Miniati
(ETHZ - ETH Zurich)
07/12/2015, 16:35
Talk
Massive galaxy clusters (GC) are filled with a hot, turbulent and magnetised
intra-cluster medium (ICM). They are still forming under the action of gravitational instability driving supersonic accretion flows, which partially dissipate into heat through a
complex network of large scale shocks, while partly excite giant turbulent
eddies and cascade. Amongst others turbulence amplifies...
Guenter Sigl
(II. Institut für theoretische Physik, Universität Hamburg)
07/12/2015, 16:55
Talk
We will present work on the chiral magnetic instability in the context of hot neutron stars and its possible role for magneto genesis in the early Universe. Whether a chiral asymmetry in the electron sector, induced for example by the electroweak interaction, leads to growing helical magnetic fields depends on many factors that will be discussed in this talk.
