12 research outputs found
Aspects of emergent geometry in the AdS/CFT context
We study aspects of emergent geometry for the case of orbifold superconformal
field theories in four dimensions, where the orbifolds are abelian within the
AdS/CFT proposal. In particular, we show that the realization of emergent
geometry starting from the N=4 SYM theory in terms of a gas of particles in the
moduli space of vacua of a single D3 brane in flat space gets generalized to a
gas of particles on the moduli space of the corresponding orbifold conformal
field theory (a gas of D3 branes on the orbifold space). Our main purpose is to
show that this can be analyzed using the same techniques as in the N=4 SYM case
by using the method of images, including the measure effects associated to the
volume of the gauge orbit of the configurations. This measure effect gives an
effective repulsion between the particles that makes them condense into a
non-trivial vacuum configuration, and it is exactly these configurations that
lead to the geometry of X in the AdS x X dual field theoryComment: 24 page
Particle Physics Implications and Constraints on Dark Matter Interpretations of the CDMS Signal
Recently the CDMS collaboration has reported an excess of events in the
signal region of a search for dark matter scattering with Silicon nuclei. Three
events on an expected background of 0.4 have a significance of about 2 sigma,
and it is premature to conclude that this is a signal of dark matter.
Nonetheless, it is important to examine the space of particle theories capable
of explaining this excess, to see what theories are capable of explaining it,
and how one might exclude it or find corroborating evidence in other channels.
We examine a simplified model containing a scalar mediator particle, and find
regions consistent with the CDMS observations. Bounds from colliders put
important restrictions on the theory, but viable points, including points
leading to the observed thermal relic density, survive.Comment: 16 pages, 6 figure
Numerical tests of AdS/CFT at strong coupling
We study various correlation functions (two and three point functions) in a
large matrix model of six commuting matrices with a numerical Monte Carlo
algorithm. This is equivalent to a model of a gas of particles in six
dimensions with a confining quadratic potential and logarithmic repulsions at
finite temperature, where we are measuring the leading order non-gaussianities
in the thermal fluctuations.
This is a simplified model of the low energy dynamics of N=4 SYM at strong
coupling. We find strong evidence that the simplified matrix model matches with
the dual gravitational description of three point functions in the AdS/CFT
correspondence.Comment: 23 pages, 7 figures, revtex. v2: minor correction
Dark Matter in the Coming Decade: Complementary Paths to Discovery and Beyond
In this report we summarize the many dark matter searches currently being
pursued through four complementary approaches: direct detection, indirect
detection, collider experiments, and astrophysical probes. The essential
features of broad classes of experiments are described, each with their own
strengths and weaknesses. The complementarity of the different dark matter
searches is discussed qualitatively and illustrated quantitatively in two
simple theoretical frameworks. Our primary conclusion is that the diversity of
possible dark matter candidates requires a balanced program drawing from all
four approaches.Comment: Report prepared for the Community Summer Study (Snowmass) 2013, on
behalf of Cosmic Frontier Working Groups 1-4 (CF1: WIMP Dark Matter Direct
Detection, CF2: WIMP Dark Matter Indirect Detection, CF3: Non-WIMP Dark
Matter, and CF4: Dark Matter Complementarity); published versio
A Monte-Carlo study of the AdS/CFT correspondence: an exploration of quantum gravity effects
In this paper we study the AdS/CFT correspondence for N=4 SYM with gauge
group U(N), compactified on S^3 in four dimensions using Monte-Carlo
techniques. The simulation is based on a particular reduction of degrees of
freedom to commuting matrices of constant fields, and in particular, we can
write the wave functions of these degrees of freedom exactly. The square of the
wave function is equivalent to a probability density for a Boltzman gas of
interacting particles in six dimensions. From the simulation we can extract the
density particle distribution for each wave function, and this distribution can
be interpreted as a special geometric locus in the gravitational dual. Studying
the wave functions associated to half-BPS giant gravitons, we are able to show
that the matrix model can measure the Planck scale directly. We also show that
the output of our simulation seems to match various theoretical expectations in
the large N limit and that it captures 1/N effects as statistical fluctuations
of the Boltzman gas with the expected scaling. Our results suggest that this is
a very promising approach to explore quantum corrections and effects in
gravitational physics on AdS spaces.Comment: 40 pages, 7 figures, uses JHEP. v2: references adde