I summarize the latest constraints on dark matter and dark energy from the cosmic microwave background, large-scale structure, lensing, LyA forest clustering, etc, focusing on the following questions: By postulating complicated unseen matter with sufficiently many free parameters, one can fit almost any observational data, so how can we test the underlying physics in a model-independent way? What current and upcoming cosmological constraints can be robustly connected with dark matter properties that can be probed experimentally?
[Y6.002] A Rejuvenated Universe Without Initial Singularity
Eric Gawiser (Physics Dept., U.C. San Diego)
The Hot Big Bang plus inflation is the standard model of the
early universe. I will present a new cosmological model
which uses the observed cosmic dark energy as initial
conditions for an inflationary phase which mimics a Hot Big
Bang. This inflationary phase (dubbed rejuvenation) will be
produced if the effective cosmological constant increases
with time. The universe undergoes superexponential expansion
until it resumes radiation domination, leaving it identical
to a Hot Big Bang in all measurable respects but avoiding an
initial singularity. This process can produce adiabatic
density perturbations as favored by recent observations of
Cosmic Microwave Background anisotropy, although a blue tilt
to the primordial power spectrum is predicted.
[Y6.003] Neutron Diffusion and Nucleosynthesis in an Inhomogeneous Big Bang Model
Juan Lara (Center for Relativity, University of Texas at Austin)
This talk describes the evolution of a Big Bang
Nucleosynthesis model with an inhomogeneous baryon
distribution. The IBBN model is a spherically symmetric
model with a high baryon density core and a low baryon
density outer region. At an initial temperature T = 100
GK the model uses a high-to-low density contrast is R =
800.0 and the high density volume fraction f_v = 1/8 as
example values. Neutrons diffuse from the high density
region to the low density region. Weak reactions convert
some of the protons in the high density region into
neutrons, which then diffuse to the low density region and
get converted back to protons. Around T = 0.9 GK
nucleosynthesis occurs slightly earlier in the core,
depleting neutrons more rapidly. Neutrons then back diffuse
from the outer region into the core. The degrees of neutron
and proton diffusion and neutron back diffusion depend on
when the diffusion length d_l expands beyond the
distance scale r_i. For a set baryon-to-photon ratio
\eta_10 = 5.5 the talk shows how the value of r_i
affects neutron diffusion and determines the overall
production of ^4He.
[Y6.004] LSST as a precision probe of dark energy
Tony Tyson, David Wittman (Bell Labs, Lucent Technologies), Joe Hennawi, David Spergel (Princeton University), The LSST Collaboration
The distortion of images of high-redshift background
galaxies can be used to probe the intervening mass
distribution. This weak gravitational lens effect can be
used to detect clusters of dark matter, weigh them, image
their mass distribution, and determine their 3-D location.
The number of mass clusters detected and their redshift
distribution are very sensitive to the density of matter
Ømega_m and the equation of state of dark energy w. The
degeneracy curve in the Ømega_m -- w plane is nearly
orthogonal to that from the CMB measurements, so that a
combination of CMB data with weak lensing by clusters can
yield precision measurements of Ømega_m and w,
independently of the supernova observations. The planned
Large Synoptic Survey Telescope (LSST) will repeatedly
survey 14,000 square degrees of the sky to unprecedented
depths. LSST will create a 3-D mass tomographic assay of
mass overdensities back to half the age of the universe by
measuring the weak gravitational shear and color-redshift of
billions of high redshift galaxies. LSST measurements of
shear versus source redshift and lens redshift constrain the
dark energy density and equation of state. By simultaneously
measuring a range of properties of cosmic shear and cluster
abundance, the LSST is able to provide a number of
independent constraints on the dark energy density and the
equation of state. LSST will determine the dark energy
equation of state w to within one percent, sharply
constraining the nature of dark energy. See the web site
http://lssto.org for plots.
[Y6.005] Collapse of Lyman Alpha Clouds to Galaxies with Flat Rotation Curves
Nathan Currier, Stirling Colgate (LANL), Michael Warren (Lanl)
We hypothesize that a lyman alpha cloud does not need to
transport angular momentum outward as it collapses to form a
galaxy with a flat rotation curve, M_interior \propto R.
A cloud with uniform density and solid-body rotation
naturally has the angular momentum distribution of a disk
with a flat rotation curve, so the cloud should be able to
collapse to a spiral galaxy while conserving the angular
momentum and radial ordering of all mass elements. To test
this hypothesis, we will use a simplified nbody +
hydrodynamics code which can rigorously banish all transfer
of angular momentum while still preserving the essential
features of dissipative baryonic collapse.
[Y6.006] Status of the U.S. cold dark matter axion search
Stephen J. Asztalos, L. J Rosenberg, D. B Yu (MIT), C. Hagmnann, D. Kinion, W. Stoeffl, K. van Bibber (Lawrence Livermore National Laboratory), P. Sikivie, D. B. Tanner (University of Florida, Gainesville), D. M. Moltz (Lawrence Berkeley National Laboratory,)
The axion is a well motivated particle whose discovery would
explain the apparent absence of CP violation in the strong
sector. It's abundant production in the early universe also
makes the axion a compelling cold dark matter candidate. The
axion's couplings to matter are thought to be extremely
small, however, its conversion into two photons can be
stimulated with the help of a resonant cavity and a strong
magnetic field. We report on the status of our ongoing cold
dark matter axion search and discuss both short- and
long-term strategies. The latter includes development of
extremely low noise RF SQUID amplifiers, which will enable
us to scan the allowed mass range much more expeditiously.
[Y6.007] Accessibility of supersymmetric models to CDMS and other direct search experiments
Vuk Mandic (UC Berkeley), CDMS Collaboration
One of the most attractive features of the supersymmetric
extensions of the Standard Model of particles is a natural
non-baryonic cold dark matter candidate. We review
accessibility of such supersymmetric models to the Cryogenic
Dark Matter Search experiment, as well as to the other
direct dark matter search experiments. In particular, we
study theoretical constraints of the supersymmetric
parameter space, such as the minimal supergravity (mSUGRA)
framework. We also examine the possible complementarity of
direct search experiments with other experimental results,
such as the measurement of the anomalous magnetic moment of
muon.
[Y6.008] Results from the CDMS 2001/2002 run at the Stanford Underground Facility
Tarek Saab (Stanford University), CDMS Collaboration
In the fall of 2001 the CDMS II (Cryogenic Dark Matter
Search) experiment deployed a set of 6 ZIP (Z-dependent
Ionization and Phonon) detectors at the Stanford shallow
underground facility. The 4 250g Ge detectors, and 2 100g Si
detectors, are able to perform a direct detection search for
weakly interacting massive particles (WIMPs) by
discriminating among nuclear recoils, due to neutrons and
WIMPs, from electron recoils, due to gammas and betas, down
to recoil energies below 10 keV. The goals of this run are
to improve upon the 1999 CDMS I upper limit as well as to
precisely measure the backgrounds on these detectors in
preparation for their deployment at the Soudan deep site in
the summer of 2002.
[Y6.009] Background issues for the Cryogenic Dark Matter Search
Laura Baudis (Stanford University), CDMS Collaboration
The Cryogenic Dark Matter Search (CDMS) experiment uses
phonon and ionization mediated Ge and Si detectors operated
below 50 mK to search for weakly interacting massive
particles (WIMPs), which are excellent candidates for the
dark matter in our universe. Since predicted WIMP event
rates are well below 1 event per kg of detector material per
day, achieving extremely low background rates is a central
issue for this type of experiment. We discuss the most
important sources of backgrounds, as well as methods to
predict and suppress them. We compare our predictions to the
current data of the CDMS experiment and give an estimation
of the expected background rates, and thus sensitivity to
dark matter particles, at the final deep site location of
the experiment.
[Y6.010] Fundamental Dynamics of Black Hole Physics
Nassim Haramein (Anodos Foundation)
The dynamics of rotating, charged black holes, obeying the Kerr-Newman metric is presented. These dynamical high-density, gravitationally collapsing, black hole systems for stellar, galactic, intergalactic and cosmogenesis appear to obey similar constraints on their mass, apparent density and radius. Under these extreme conditions, the gravitational force becomes "balanced" with the larger coupling constant of the electromagnetic force. Thus, the gravitational attraction forms dynamic pseudo equilibrium with the plasma dynamics surrounding the black holes. Thermodynamic-type processes occupy a role in energy transfer between gravitational attraction and electro-dynamic repulsion. Solving the modified Einstein-Maxwell's equations under high magnetic field conditions, with additional thermodynamic conditions, leads to a good description of the processes occurring externally, near and in the event horizons of the Kerr-Newman geometry and leads to a unification possibility. Reference; N. Haramein, Bull. Amer. Phys. Soc. AB06, 1154(2001)