Cosmo-torun May 2009

cosmo-torun@cosmo.torun.pl

1 participants
2 discussions

some notes after today's talk - LDM
by Boud Roukema 22 May '09

22 May '09

witam cosmo-torun * circular polarisation from synchrotron processes? Kennett & Melrose, 1998, PASA, 15, 211 http://www.atnf.csiro.au/pasa/15_2/kennett/paper/node3.html > In some sources it may be that the relativistic > particles are electron-positron pairs (e.g., Wilson & > Weiler 1997). Electrons and positrons contribute with > the same sign to the linearly polarized component and > with the opposite sign to the circularly polarized > component. If the distributions of electrons and > positrons are the same the wave modes can have no > circular component and, more importantly, the intrinsic > circular polarization from the synchrotron radiation > sums to zero. So if we have different distributions of electrons and positrons, then we get a circular polarisation component. i'm sure there must be more basic texts on this subject... pozdr boud

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non-baryonic dark matter now detected at 8.2 sigma: DAMA/NaI + DAMA/LIBRA - Bernabei et al. ArXiv:0804.2741
by Boud Roukema 20 May '09

20 May '09

witam cosmo-torun, The DAMA detections of nbDM seem to be getting even stronger! Bernabei et al. ArXiv:0804.2741 now have their annual modulation signal of non-baryonic dark matter from the Galactic DM Halo detected "at 8.2 sigma CL": DAMA/NaI + DAMA/LIBRA. Figures 2, 4 and 8 are especially impressive. Savage et al. have a nice article ArXiv:0808.3607 showing the regions of parameter space for WIMPS for which are consistent with both the DAMA detection and all the non-detections in other experiments. E.g. spin-dependent, proton-only couplings for a particle mass of about 5-9 GeV are one region compatible with all the data. This doesn't stop LDM (light dark matter) *also* being a correct hypothesis for nbDM - multiple DM particles may contribute together to non-baryonic DM. pozdr boud

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Cosmo-torun May 2009