Download presentation
Presentation is loading. Please wait.
Published byHugo Stafford Modified over 9 years ago
1
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Niayesh Afshordi
2
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection Roya Mohayaee (IAP, Paris) Ed Bertschinger (MIT) Hierarchical Phase Space Structure of Dark Matter Haloes: Tidal debris, Caustics, and Dark Matter annihilation: arXiv:0812.2244 Hierarchy in the Phase Space and Dark Matter Detection: in preparation
3
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection 22% of density of Universe consist of DM No clear non-gravitational detection Tentative anomalies may come from WIMP’s: PAMELA, positron excess ATIC e + -e - excess WMAP haze at Galactic center INTEGRAL 511 keV excess DAMA/LIBRA direct detection signal ?????
4
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection Gravitational evidence for DM comes from potential: s d 3 x ½ (x)/|x-x’| Direct detection: ½ (x) at solar system Indirect detection (annihilation): s d 3 x ½ ( x) 2 WIMP detection is much more sensitive to DM sub-structure: Boost ´ h ½ 2 i / h ½ i 2 -1
5
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection CDM is really cold v CDM » 10 -11 c Phase space density remains constant in lieu of collisions (Liouville Theorem): At CDM freeze out: Within our Galaxy: Most of the phase space is empty!
6
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection Phase space of CDM haloes is mostly empty, and has a rich structure: Hierarchy of tidal debris and sub n -haloes Fundamental discreteness Boost in DM annihilations DM direct detection can show signs of sub- structure
7
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection Bound sub-haloes (cluster in real/phase space) Tidal debris (cluster in initial conditions) Fundamental discreteness analogous to galaxy shot noise NGC 3923 Kuhlen, Diemand, et al.
8
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection
9
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection Evolution of tidal debris is simple in action- angle space
10
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection Distribution in action space is a lattice which becomes finer in time Afshordi et al. 08 McMilllan & Binney 08
11
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection Discrete/cold structures in action space project into catastrophes into real space NGC 3923 Catastrophes of light ray distribution Catastrophes in stellar distribution cusp fold
12
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection Tidal debris: h f(J 1 ) f(J 2 ) i/ | J 1 -J 2 | -1.6 Fundamental discreteness: h f(J 1 ) f(J 2 ) i/ ± 3 (J 1 -J 2 ) Boost = h ½ 2 i / h ½ i 2 -1 » O(1) + 3x10 5 ( ½ / ½ crit ) -3/2 tidal debris discreteness
13
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection Total boost Local Boost
14
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection Stable clustering in phase space can be used to describe bound sub n -halo hierarchy Kuhlen, Diemand, et al. within virial radius at solar system Boost » 10 6 ( ½ crit,0 / ½ ) Afshordi et al. in prep.
15
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection Temporal auto-correlation of DM detection in several years… Afshordi et al. in prep.
16
Miami 2008, Fort Lauderdale, Dec. 2008Niayesh Afshordi, Perimeter Institute Hierarchy in the Phase Space and Dark Matter Detection Phase space of CDM haloes is mostly empty, and has a rich structure: Hierarchy of tidal debris and sub n -haloes Fundamental discreteness Boost in DM annihilations DM direct detection can show signs of sub- structure
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.