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ToK Warszawa meeting - Rough Notes Thu 15 Feb 2007

These are just rough notes - feel free to correct them, add links, etc.

Hector Rubinstein - stockholm - magnetic fields

Magnetic fields on kpc scales exist. They may exist on intergalactic scales - it's unclear whether or not their origin is primordial.

CMB - Planck - may be able to detect magnetic fields present at the epochs not long after nucleosynthesis and recombination

it is well known that photon has a thermal mass - about 10^{-39} [units =eV?] which is extremely small - related to electron loops

Maxwell eqns -> Proca eqns WikipediaEn:Proca_action

m_photon < 10^-26 eV

\exists galactic mag fields at z \approx 3 making dynamo mechanisms difficult to explain them

Boehm - LDM hypothesis

511 keV detection

Leventhal(sp?) 199x ApJ OSSE 3 components Purcell et al 1997


stars - SNe, SNII, WR compact sources - pulsars, BH, low mass binaries

- most excluded because they would imply 511keV from the disk - SNIa - need large escape fraction and explosion rate to maintain a steady flux - low mass X-ray binaries - need electrons to escape from the disk to the bulge

MeV scale

dm + dm -> e^- + e^+ e+ loses energy -> positronium e+e- -> positronium decays

para-positronium 2 gamma - monochromatic wih 511keV ortho-positronium 3 gamma - continuum


positron emission should be maximal with highest DM concentration (n^2 effect?)

cdm spectrum

does NOT produce CDM-like power spectrum???

- at 10^9 M_sun essentially CDM-like

- by 10^6 M_sun, the difference would be important


Ascasibar et al 2005, 2006


* through F- 511keV * through Z' relic density

link with neutrino mass

interaction/decay diagrams ->

link between neutrino mass and DM cross section:

%$ m_\nu = \sqrt{ \sigma \nu \over 128 \pi^3 } m_N^2 ln{ \Lambd^2/m_N^2 } $%

\sigma_\nu well-known for relic density \sim 10^{-26} cm^3/s

\Rightarrow m_N < 10 <a class=MeV" class="mmpImage" src="/foswiki/pub/Cosmo/ToK070215RoughNotes/_MathModePlugin_731486621df83fabc7268c4eba1fd524.png" /> to fit neutrino data

BBN: 1MeV < m_N

low energy Beyond SM

MeV DM has definitely escaped all previous low energy experiments due to lack of luminosity



  • explains low value of neutrino masses
  • detection at LHC may be possible but requires work
  • back to SUSY -> snu-neutralino-nu ?

Conlon - hierarchy problems in string theory: the power of large volume

planck scale 10^18 GeV ... cosm constant scale (10^-3eV)^4

- large-volume models can generate hierarchies thorugh a stabilised exponentially large volume

- predicts cosmological constant (but about 50 orders of magnitude too large - solving this problem is left to the reader/audience)

G\"unther Stigl - high-energy c-rays, gamma-rays, neutrinos

HESS - correlation of observations at GC with molecular cloud distribution

KASCADE - has made observations

Southern Auger - 1500km^2 - in Chile/Argentina

Hillas plot

c-rays at highest energies could be protons, could be ions

- most interactions produce pions; pi^\pm decays to neutrinos pi^0 decays to photons (gamma-rays)

  • origin of very high energy c rays remains one of the fundamental unsolved questions of astroparticle physics - even galactic c ray origin is unclear
  • acceleration and sky distribution of c rays are strongly linked to the strength and distribution of cosmic magnetic fields - which are poorly known
  • sources probably lie in fields of \mu-Gauss
  • HE c-rays, pion-production, gamma-ray/neutrinos - all three fields should be considered together; strong constraints arise from gamma-ray overproduction

Khalil - DM - SUSY - brane cosmology

(British University in Egypt = BUE)

- friedmann eqn modified in 5D (brane model)

- dark matter relic abundance
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Topic revision: r1 - 16 Feb 2007, BoudRoukema
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