Презентация на тему: " 1 Additional observable evidences of possible new physics Lecture from the course Introduction to Cosmoparticle Physics." — Транскрипт:
1 Additional observable evidences of possible new physics Lecture from the course Introduction to Cosmoparticle Physics
2 0. Remembering of the learned material Baryonic asymmetry of Universe Evidences in favour of dark matter Reasons for inflation
3 1. Cosmic rays of middle and high energy a) common information UHECR (EAS) Interstellar medium: Natural sources: SN, pulsars, secondary origin Problems: sources, parameters of interstellar medium and halo, solar modulation THERE ARE MANY UNCERTAINTIES
4 1. Cosmic rays of middle and high energy b) diffuse gamma-radiation ? ??? From GC From high latitude there is unexplained -background Most conservative predictions are used.
5 1. Cosmic rays of middle and high energy c) antiprotons diffusive propagation Secondary origin: Dipping of the spectrum at low energy
6 1. Cosmic rays of middle and high energy c) antiprotons ? c1) antideuterium Most conservative predictions are used. Expected secondary antiD Hypothetical primordial antiD (from PBH)
7 1. Cosmic rays of middle and high energy d) positrons E>0.1 GeV synchrotron and Compton losses of energy !
8 1. Cosmic rays of middle and high energy d) positrons ? Most conservative predictions are used.
9 1. Cosmic rays of middle and high energy e) possible origin Besides natural astrophysical origin, CR can originate from annihilation or/and decay of dark matter particles in halo of our Galaxy, or evaporation of PBH.
10 2. Cosmic rays of ultra high energy Content, propagation, origin of UHECR are the subject of modern investigations. Anisotropy of UHECR does not allow to identify sources (to connect with our Galaxy or other galaxies). At UHE many known particles should experience energy losses. Macroscopic magnitudes of the energy!
11 2. Cosmic rays of ultra high energy a) protons and nuclei Spectrum in case of homogeneous distribution of sources Spectrum in case of all sources are concentrated in Local Cluster (within 20 Mpc) Energy loss rate Greisen-Zatsepin-Kuzmin cut-off
12 2. Cosmic rays of ultra high energy b) gamma c) electrons and positrons Absorption probability Energy loss rate (See also slide 7.) Galactic scale Universe scale Galactic scale
13 2. Cosmic rays of ultra high energy d) possible origin Magnetosphere of pulsars Accretion disk Cosmic strings Decay or annihilation of hypothetical supermassive relic particles in extensive halo UHE neutrino mediation: Fargion mechanism anisotropy in Galaxy - homogeneously in Universe - isotropic
14 3. Gamma-bursts Gamma-ray bursts (GB) are discovered in 1973, and after launching interplanetary stations they are observed with frequency 1 per day. Their typical characteristics: In some gamma-bursts a broad absorption lines are observed at E~ keV. It can be treated as a resonant absorption by plasma in magnetic field with Moreover, sometimes emission lines at E400±50 keV are observed. It can be treated as a e + e - -annihilation in gravitational field with These led to conclusion that gamma-bursts can be connected with neutron stars, energy release of GB is estimated as ~ erg. Short time ( t~ s) variability of some gamma-bursts tells about compact size of the source: ~ tc~3000 km
15 3. Gamma-bursts However, no gamma-bursts were identified with visible sources. Moreover, GB events are distributed on the celestial sphere isotropically. In the end of 1990 s, there appeared event of GB which has been identified with a distant galaxy at z~1! Energy release of GB might be, in case of isotropic source, ~ erg! (GRB , z=1.6, 1.4·10 54 erg) For comparison: novae – erg, supernovae – erg (in the maximum ~10 42 erg/s). possible origin Cosmic strings (mainly, for short time GB; problematic connection with galaxy), binary NS merger, SN (poor quantitative predictions), ???
16 4. Difficulties of Cold Dark Matter scenario 1).An excessive number of dwarf galaxies are predicted: e.g. in Local Group a ratio between giant and small galaxies is ~1:10, while CDM model predicts ~1:100. 2)Cusp-crisis: analytic calculations, N-body simulations in framework of CDM model give a singular central density distribution of dark matter halos (galaxies) in contradiction to observations. Possible solution: a)self-interacting DM particles (free traveling length is ~galactic size) b)annihilating DM particles (a specific behavior of annihilation cross section is required to provide a small value in early Universe and large one on the galactic stage) c)complicated dynamics in GC (several massive black holes, …)
17 4. Difficulties of Cold Dark Matter scenario 3)Clumpiness: Existence of small scale inhomogeneities (clumps) are predicted for CDM. Clumps form on pregalactic stage (of structure formation in Universe) and most of them are destroyed in galaxies. In modern epoch, about 10 -(2-3) mass of galaxies can be in form of clumps. Characteristics of the clumps as predicted: Consequences: amplification of annihilation (in ~ times). M min depends on type of DM particle. For neutralino typically: 4)Caustic rings: Dynamics of contraction (infall) of CDM into Galaxy leads to an existence of flows of CDM of spherical form and increased density.