Task B: Theoretical Particle Astrophysics

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Estella Rodgers
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1 Task B: Theoretical Particle Astrophysics

2 Cosmology/! Particle/Nuclear Astrophysics Physics Particle dark matter Dark energy Inflation Neutrino astrophysics Ultrahigh-energy cosmic rays Baryogenesis Extra-dimensional/string cosmology; variable constants;.

3 History of Task B 1999: MK arrives as professor : ~$100K/year (MK summer salary plus student) : ~$150K/year (MK summer salary, student, plus 2nd student or 50% postdoc) 2006: Sean Carroll arrives as Moore SRA : $200K/yr (added $50K for SC research expenses) 2007: Chris Hirata arrives as asst professor Current request: significant increase to funding level commensurate with three productive senior investigators

4 Accomplishments of program, : Postdocs trained! Piero Ullio, (SISSA, tenured)! Ken Nollett, (permanent, Argonne nuclear theory)! Peng Oh, (tenured, UCSB)! Andrew Benson, (SRF, Caltech)! Asantha Cooray, (tenured, UC Irvine)! Arielle Phillips, (postdoc, Amherst)! Andriy Kurylov, (McKinsey)! Milos Milosavljevic, (asst prof, UT Austin)! Nicole Bell, (asst prof, Melbourne)! Elena Pierpaoli, (asst prof, USC)! Steve Furlanetto, (asst prof, Yale/UCLA)! Stefano Profumo (asst prof, UC Santa Cruz)

5 Accomplishments of program, : Graduate students trained! Jonathan Pritchard, 2007 (Hubble Fellow, Harvard)! Michael Kesden, 2005 (postdoc, CITA)! Nevin Weinberg, 2005 (postdoc, Berkeley)! Kris Sigurdson, 2005 (asst prof, UBC)! Michael Santos, 2002 (STScI)! Xuelei Chen, 1999 (professor, Beijing)! Catherine Cress, 1999 (professor, KwaZulu-Natal)! Alexandre Refregier, 1998 (permanent, CEA-Saclay)

6 Accomplishments of program, : Research Accomplishments! Several hundred refereed articles including, e.g.,! Parity violation in CMB! Inflation with broken scale invariance! Intrinsic galaxy alignments and cosmic shear! First-star contributions to cosmic infrared background! The big rip! Separation of gravitational waves and weak lensing in CMB polarization! Dark matter, dwarf galaxies, and the equivalence principle! Solar system tests of f(r) gravity theories! A new CMB upper limit to short-wavelength gravitational waves! Novel effects of and telescope searches for decaying dark matter! Review articles on CMB, dark matter, dark energy, universal extra dimensions, halo clustering, and 21-cm probes of high-z universe

7 People to be affiliated with Caltech theoretical cosmology and particle astrophysics Faculty: Marc Kamionkowski (Professor) Sean Carroll (Senior Research Associate [i.e., research professor Chris Hirata (assistant professor, arriving Fall 2007) Andrew Benson (Senior Research Fellow [i.e., research asst prof]; Moore) Postdocs: Dan Babich (Moore prize scholar) Shin ichiro Ando (Fairchild Fellow) Daisuke Nagai (Fairchild Fellow) Matt Johnson (Moore Fellow) Annika Peter (Task B)

8 People to be affiliated with Caltech theoretical cosmology and particle astrophysics Graduate Students: Tristan Smith (5th year; DoE) Lotty Ackerman (5th year; DoE) Anthony Pullen (4th year; NSF Fellow) Adrienne Erickcek (4th year; NSF Fellow---TA) Dan Grin (4th year; Moore Fellow) Martin Springer (4th year; Oxford student with Benson) Visiting Associates: Asantha Cooray (UC, Irvine) Kris Gorski (JPL) Elena Pierpaoli (USC) Steve Furlanetto (UCLA) Visitors: Robert Caldwell (Dartmouth; 2 months; fall 2007) Rennan Barkana (Tel Aviv; 6 months) Plus ~3-4 incoming students

9 Our work is relevant for SNAP/JDEM CMB experiments (WMAP, Planck, CMBPOL GLAST/VERITAS/STACEE/. Collider experiments Neutrino experiments CDMS, etc. Super-K, IceCube. LSST SDSS/2dF. AMS.

10 Benefits of this program to DoE DoE funding heavily leveraged by Caltech Maintains theoretical activity at major center for experimental particle astrophysics and early-universe cosmology Supports training of some of the best postdocs and students in the field Grad student support goes only to advanced students, when they are most productive

11 MK: Current research topics CMB and inflationary gravitational waves Phenomenology of Chern-Simons gravity Tests for statistical isotropy Various probes of decaying dark matter Galactic-halo merger rates New telescope probe of expansion history and dark Supersymmetric dark matter

12 Some Recent Research

New probe of primordial GWs Smith, Pierpaoli, MK, PRL 2006 Conventional way to probe them: 1) low-l plateau versus peaks 2) curl mode polarization New

13 New probe of primordial GWs Smith, Pierpaoli, MK, PRL 2006 Conventional way to probe them: 1) low-l plateau versus peaks 2) curl mode polarization New approach: Small-wavelength GWs behave as massless particles. They contribute to the energy density of the Universe and affect CMB fluctuations and large-scale structure.

New limits on gravitational-wave energy density at frequencies 10-16 - 10-11 Hz.

14 New limits on gravitational-wave energy density at frequencies Hz. At higher frequencies, constraints now comparable, and in future, stronger, than BBN, constraints Smith, Pierpaoli, MK (PRL 2006)

15 Galilean equivalence for Galactic dark matter Kesden and MK, 2006 Does dark matter fall the same way in a gravitational field as ordinary matter? Models that couple dark matter and dark energy may lead to additional 1/r 2 force law that mimics a Newton s constant G that is different for dark matter. We thus consider force law for dark matter that is bigger by factor (1+" 2 ).

16 Tidal Disruptions Galaxies form hierarchically; smaller satellites are tidally disrupted in the haloes of larger hosts Several stellar streams have been found in the MW, e.g. the Sgr dwarf at 24 kpc disrupted stars retain similar orbits to satellite; trail/lead with gain/loss in energy

17 Stellar Streams of Sgr Dwarf

18 Tidal Streams Probe Fifth Force

19 Conclusions A coupling between dark matter and dark energy naturally leads to a fifth force that acts effectively as a violation of the equivalence principle for dark matter Tidally disrupting galaxies provide perfect test; core is DM-dominated but not streams Attractive DM-force sweeps core ahead; leading-to-trailing ratio suppressed. Current data show roughly equally populated tidal streams; already suggests Newton constant for dark matter differs by no more than 10% from ordinary matter. More detailed analysis of current data should be sensitive at the ~ 1% level

Weak gravitational lensing of CMB

Weak gravitational lensing of CMB (Recent progress and future prospects) Toshiya Namikawa (YITP) Lunch meeting @YITP, May 08, 2013 Cosmic Microwave Background (CMB) Precise measurements of CMB fluctuations