Non-Gaussian effects in the cosmic microwave background (CMB) can arise either from the primordial phase of the universe or from the subsequent non-linear evolution. I will focus on the latter point and review the perturbation theory beyond linear order. I will detail how the kinetic theory can be used in cosmology to derive the evolution of perturbations for polarized radiation. Finally I will present why the collapse of dark matter is the main source of non-Gaussianity in the CMB on small scales.

The South Pole Telescope (SPT) is a 10-meter telescope optimized to study of dark-energy and inflation through arcminute resolution maps of the cosmic microwave background (CMB). Construction and commissioning were completed in January 2007, and since then we have acquired two years of data. Using these observations we recently published the first detection of galaxy clusters selected with the Sunyaev-Zel'dovich (SZ) effect. Through the SZ effect, we will detect a large number of clusters and trace the evolution of dark energy through its effect on the growth of large scale structure. In addition, the survey data will provide an improved measurement of the temperature power spectrum of the CMB up to arcminute scales which will
improve constraints on the power spectral index of primordial scalar perturbations. In this talk I provide an overview of the SPT instrument and discuss the prospects for cosmology.

Noble liquid detectors are changing in a fundamental way the field of direct dark matter searches. They feature excellent discrimination between minimum ionizing events - due to background radioactivity - and nuclear recoils - the signature of WIMP dark matter interactions. Their unmatched promise of a rapid scaling of the target mass (by 2-3 orders of magnitude!) and of a corresponding increase in sensitivity is driving a large number of researchers into the field: it's the 21st century gold rush of astroparticle physics. Will they provide the first successful exploration of the dark sector? Finally, I will present very recent results from the Borexino solar neutrino experiment. I will also discuss how the technology developed in the context of solar neutrino searches will impact future direct dark matter searches.

The direct detection of gravitational waves will provide a
revolutionary new probe of the most energetic processes in the
universe. The 4 km long LIGO interferometers have demonstrated the sub-attometer displacement sensitivity (< 10^{-18} m/ Hz^{1/2}) required to place upper limits on the neutron star/neutron star merger out to the Virgo galaxy cluster. Such mergers are thought to be the progenitors of short gamma-ray bursts and provide an ideal "golden event" signal for direct GW detection. Compact binary coalescences also offer one of direct tests of the neutron star equation of state, of the internal dynamics of supernovae, and of strong field general relativity.
An aggressive R&D program, Advanced LIGO, is underway to increase the interferometer stored power 30-fold (to 750 kW), develop new low noise readouts, and increase the detector sensitivity by an order of magnitude.In the next 5 years, Advanced LIGO will observe neutron star mergers and other gravitational wave events regularly, beginning a new era of gravitational astronomy.

Viewed at very high energies, the universe is a place of powerful astrophysical engines driving accelerators that reach far greater energies than anything built on earth. By studying the products of these accelerators (such as cosmic rays and gamma-rays), we can not only learn a great deal about the astrophysics of these sources, but probe a variety of questions in particle physics and cosmology. A new generation of imaging atmospheric Cherenkov telescopes (IACTs),designed to detect VHE (100 GeV-10 TeV) gamma-rays, has radically altered our picture of the very high-energy gamma-ray sky. One such instrument is the recently-commissioned IACT array VERITAS, which saw first light in April 2007. I will discuss results from the first two years of the VERITAS observing program and the guidance that they offer for the next few years of the VERITAS program. The impact of (and synergy with) the recently-launched Fermi satellite, which promises to similarly revolutionize gamma-ray astronomy in the 20 MeV to 300 GeV band, will also be discussed, along with long-term directions for the field.

Gravitational-waves are thought to be emitted by a wide variety of sources both astrophysical and cosmological in origin. While it is possible to identify individual nearby sources such as galactic pulsars or neutron-star/black-hole coalescences, other sources--each individually unresolvable--will conspire to produce a stochastic background. The angular distribution of the stochastic background is not easily predicted, and so we are faced with a challenge: stochastic searches should be flexible enough to accommodate a wide variety of distributions, but in doing so, they must not introduce so many parameters as to hamper the sensitivity of the search. In this talk I will present an algorithm that addresses the issue of how to detect an anisotropic stochastic background with little prior information about the nature of the anisotropy.

At present, the (quasi-)equilibrium structure of self-gravitating,
cold, collisionless material (a.k.a. dark matter) is studied using
N-body simulations, which give us the dynamical properties of DM
halos, like the radial density profile. However, the physics behind
this, i.e. the physics of collisionless relaxation is not fully
understood. I'll describe the recent progress in this field.

The WMAP team has recently published the results of five full years of observing the centimeter-wavelength sky (from 23 GHz to 93 GHz). In addition to cosmological information, the data provide a unique window into the behavior of three Galactic processes: synchrotron radiation, free-free emission from ionized hydrogen, and thermal dust radiation. I will present a new estimate of foreground emission in the WMAP data, using a Markov chain Monte Carlo (MCMC) method, which provides maps
and error-bars for each foreground component.

Using Very Large Baseline Interferometry, it is now possible to use parallax to measure the distances to objects in the Milky Way to very high accuracy. This work suggests the Milky Way is about 50% more massive than previously thought and also shows conclusively that the Sgr A* is a black hole.

A few percent of low-mass red giant branch and asymptotic giant branch stars show surface layers with high concentrations of lithium, generated sometime after the main sequence. As lithium is readily destroyed in stellar interiors, these observations have been the focus of both observational and theoretical investigations. Necessary conditions for lithium self-enrichment are the presence of a mechanism for rapid upward transport of material from weakly hydrogen-burning layers of the star to the surface layers and a stock of 3He as raw material. The possibility that magnetic flux tubes might provide a mechanism for rapid upward transport motivated a reinvestigation of the lithium problem using the phenomenological model of ?cool bottom processing? (CBP), which provides a formal structure for investigating both downward and upward transport with distinct rates. We present a semi-analytic model of how 3He is processed into lithium in a simple conveyor-belt model of CBP, compare its consequences with the observed compositions of stellar envelopes, and compare it with numerical calculations. It is shown that the high Li stars are readily explained by this mechanism. We discuss the conditions necessary for lithium-richness and the extent to which observations of lithium may diagnose the survival of 3He during late phases of stellar evolution. Some hints appear which suggest that the Spite plateau may simply reflect "normal high Li" stars and not the remains of Big Bang 7Li.

A few percent of low-mass red giant branch and asymptotic giant branch stars show surface layers with high concentrations of lithium, generated sometime after the main sequence. As lithium is readily destroyed in stellar interiors, these observations have been the focus of both observational and theoretical investigations. Necessary conditions for lithium self-enrichment are the presence of a mechanism for rapid upward transport of material from weakly hydrogen-burning layers of the star to the surface layers and a stock of 3He as raw material. The possibility that magnetic flux tubes might provide a mechanism for rapid upward transport motivated a reinvestigation of the lithium problem using the phenomenological model of ?cool bottom processing? (CBP), which provides a formal structure for investigating both downward and upward transport with distinct rates. We present a semi-analytic model of how 3He is processed into lithium in a simple conveyor-belt model of CBP, compare its consequences with the observed compositions of stellar envelopes, and compare it with numerical calculations. It is shown that the high Li stars are readily explained by this mechanism .We discuss the conditions necessary for lithium-richness and the extent to which observations of lithium may diagnose the survival of 3He during late phases of stellar evolution. Some hints appear which suggest that the Spite plateau may simply reflect "normal high Li" stars and not the remains of BB 7Li.

Among the 117 White Papers submitted to the Cosmology and Fundamental Physics panel of the Decadal Review are several discussing expectations and prospects for detecting light from the first stars, galaxies and exotic objects. I will review some of the basic physics and astrophysics questions at stake, and the kinds of new facilities and experiments people are planning to address these issues. Note that this will be distinct set of papers from those I discussed in a recent astronomy journal club.

The small temperature anisotropy and polarization of the cosmic microwave background (CMB) radiation have been the target of numerous earth-based, baloon-born and satellite missions in the last two decades. Upcoming CMB experiments, equipped with higher sensitivity and better angular resolution, will provide us with high fidelity probes of CMB polarization state and secondaries, such as Comptonization of the CMB by the intracluster plasma, the Sunyaev-Zeldovich (SZ) effect. The CMB is essentially a snapshot of the universe at recombination and carries a valuable information about a much earlier process, cosmological inflation. Secondary effects that took place billions of years later, at redshifts of a few, such as gravitational lensing of the CMB by the intervening large scale structure and the SZ effect provide us with cosmological bounds on neutrino masses and chemical potentials as well as the dark energy equation-of-state. Rotation of the CMB polarization-plane, due to non-standard coupling of the electromagnetic field to other scalar fields, 'cosmological birefringence', can be used to set limits on the axion mass and coupling to electromagnetic fields.
Finally, spectral distortions in the SZ effect can be used to constrain non-standard scalings of the CMB temperature with redshift.

We discuss the observational constraints on dynamical dark energy in the early Universe and the cosmological implications of its coupling to matter.

All seismic isolation systems developed for Gravitational Waves
Interferometric Detectors, such as LIGO, VIRGO, and TAMA, make use of Maraging steel blades. The dissipation properties of these blades have been studied at low frequencies, by using a Geometric Anti Spring (GAS) filter, which allowed the exploration of resonant frequencies below 100 mHz. At this frequency an anomalous transfer function was observed in GAS filter. Static hysteresis was observed as well. These were the first of several motivation for this work. The many unexpected effects observed and measured are explainable by the collective movement of dislocations inside the material, described with the
statistic of the Self Organized Criticality (SOC). At low frequencies, below 200 mHz, the dissipation mechanism can temporarily subtract elasticity from the system, even leading to sudden collapse. While the Young's modulus is weaker, excess dissipation is observed. At higher frequencies the appliedstress is probably too fast to allow the full growth of dislocation avalanches, and less losses are observed, thus explaining the higher Q-factor in this frequency range. The domino effect that leads to the release of entangled dislocations allows the understanding of the random walk of the VIRGO and TAMA IPs, the
anomalous GAS filter transfer function as well as the loss of predictability of the ringdown decay in the LIGO-SAS IPs. The processes observed imply a new noise mechanism at low frequency, much larger and in addition of thermal noise.

In this seminar, I will discuss the main signatures of dark matter candidates which are described by effective quantum field theories. In this kind of models, the interaction of the dark matter particle is characterized by a dimension-full parameter, that offers different possibilities than the dimensionless coupling, typical of renormalizable quantum field theories. I will analyze the abundance and the main phenomenological signatures of these candidates from astrophysical observations and their interplay with high energy or precision experiments. I will illustrate all these ideas with a particular candidate motivated from brane-world scenarios: the branon.

I will discuss the design specifications that drove the design of the CMB polarization anisotropy experiment EBEX. In particular, I will focus on the need for detector sensitivity in order to measure the B-mode polarization signature to a chosen level, the ability to isolate and subtract foreground sources such as polarized dust signal, and need to reduce systematic error to reduce E-B mixing.

Observational indications for different types of core-collapse supernovae
and their characteristic neutrino emission will be reviewed. The various
effects associated with neutrino oscillations will be discussed. The
neutrino signals expected from different types of supernovae will be
examined as probes of supernova physics and neutrino properties.

Thermonuclear flashes in the outer layers of accreting neutron stars are observed as X-ray bursts. These bursts are instrumental in learning more about the inner parts of the neutron star: the crust and core. Usually, a neutron star accretes matter for at least several hours, before enough fuel is accumulated to trigger a flash. In rare cases, however, bursts are observed with recurrence times as short as ten minutes. We discuss the clues we gathered to try to solve this decades-old mystery.