Rachel Mandelbaum The Institute for Advanced Study, Princeton, NJ
"Constraining Galaxy Formation Scenarios and Density Profiles
with Galaxy-Galaxy Weak Lensing"

Gravitational lensing is a convenient tool for observing the total matter content
of the universe, including the dark matter. Galaxy-galaxy lensing thus allows a measure
of the matter content of galaxies and their environs, which may be compared against
optical tracers of galaxy contents to learn about the way galaxies form and evolve, and
about the nature of the dark matter halos in which they reside. I will present several useful
observational constraints from galaxy-galaxy weak lensing: (1) on the relation between
stellar mass, luminosity, and dark matter halo mass for early and late type galaxies;
(2) on the lensing profiles of field versus satellite galaxies; and (3) on the dark matter
halos and local environments of optical narrow-line and of radio-loud AGN. As I will show,
these data exist at sufficiently high S/N to make meaningful comparisons against
pre-existing N-body simulations and semi-analytic models of galaxy or AGN formation,
and future prospects for constraints from upcoming surveys are even more promising.

Donald E. Winget University of Texas at Austin
"The Physics of Crystallization in a Dense Coulomb Plasma
from Globular Cluster White Dwarf Stars"

White dwarf stars are cosmic laboratories for studying the equation of state of matter at high densities
and temperatures. They have a long history of pushing the envelope of our understanding of matter.
Nearly eighty years ago we began to come to grips with the physical nature of the structure of
white dwarf stars; the solution of the puzzle of their masses and radii in terms of an electron
degenerate equation of state was a tour de force for the quantum theory. The 1960’s saw major
advances in our theoretical understanding of the ions: a Coulomb liquid phase and ultimately ion
crystallization were predicted. I will outline the exploration of this theoretical landscape against
the backdrop of recent astronomical observations. Significant puzzles have arisen from spectroscopic
and photometric studies of white dwarf stars in the galactic disk, even with the large samples
produced by the SDSS. Asteroseismology of white dwarf stars has led to direct measurement
of stellar evolution and promises constraints on particle physics including our understanding of
electroweak theory at low energies and the properties of axions and super-symmetric particles
and gave us the first empirical probe of the extent of ion crystallization. A new frontier is opening up
from Hubble Space Telescope observations of large populations of coeval white dwarf stars in
globular clusters. Interpreting these observations challenges our understanding of the initial final
mass relation, nucleosynthesis, and basic internal white dwarf compositional structure, as well as
providing important additional confirmation of ion crystallization theory. Through the study of
white dwarf stars in the globular cluster, NGC 6397 I present our empirical evidence that
crystallization is a first-order phase transition – releasing latent heat. Most exciting is the new
tool these stars provide for measuring the Gamma of crystallization in dense Coulomb plasmas.
I will discuss the future of these important tools for cosmochronology, particle physics, and
the equation of state of matter.

Andrew Hamilton University of Colorado at Boulder
"Black Holes, Schrodinger Cats, and Particle Accelerators"

What really happens inside black holes? As first pointed out by Poisson & Israel (1990),
the classical empty (Kerr-Newman) solutions for black holes, complete with their analytic
continuations through wormholes and white holes to new universe, are subject to the mass
inflation instability. The instability has profound consequences for the interior structure of
black holes. If the instability is suppressed by large dissipation, then the typical result is
the creation of a huge amount of entropy inside the black hole, orders of magnitude more
than the Bekenstein-Hawking entropy. If the second law of thermodyamics is to be saved,
then locality must break down inside black holes, so that entropy does not accumulate inside
black holes. In effect, what happens inside the horizon of a black hole must constitute an
alternate quantum reality for each person that travels inside it. Alternatively, if dissipation is
more modest, then mass inflation will occur. Mass inflation is caused by relativistic counter-
streaming between ingoing and outgoing streams. The result is a particle accelerator of
extraordinary power: the black hole accelerates ingoing and outgoing streams through each
other to center-of-mass energies that classically far surpass the Planck energy, easily reaching
conditions as extreme as those in the Big Bang. Like the Big Bang, the conditions are not
only energetic but of low entropy. What does Nature do with this remarkable beast?

Nov. 18th

Special Event: Beatrice M. Tinsley Visiting Professor in Astronomy (visit: Nov. 3 - Dec. 4)

Geoffrey A. Blake California Institute of Technology (Caltech)  
"The Search for Infant Solar Systems"

As conduits of mass and angular momentum, circumstellar accretion disks serve as the critical
link between astrophysics and (exo)planetary science. With new spectrometers on board the
Spitzer Space Telescope and the Keck/Very Large Telescopes in Hawaii/Chile, we have used
high resolution spectroscopy to discover systems in which planet(esimal) formation is likely ongoing.
In a few cases follow up imaging with aperture synthesis arrays has directly confirmed the disk
structure inferred from spectro-photometry. This talk will present the means by which such
discoveries are made as well as a number of recent results, and speculate on future
directions in the field.

Using the excellent astrometry capabilities of the Very Long Baseline Array, we have measured
the trigonometric parallax (and the proper motions) of a number of young stars in several nearby
star-forming regions with a precision better than a few percents. This represents an improvement
by one to two orders of magnitude over previous determinations. In particular, we have found that
the distance to the core of Ophiuchus is 120 ± 4.5 pc, and we have confirmed that the mean
distance to Taurus is 140 pc. Our data also allow us to determine the 3D structure of the regions
under study. In the case of Taurus, we have shown that the total extent of the complex along the
line of sight is about 30 pc, the eastern portion being on the far side and the region around L1495
on the near side. Finally, the proper motion measurements, combined with existing radial velocities,
allow us to describe the internal kinematics of the regions under study. A full spatio-kinematical
description of star- forming regions, therefore, becomes possible.

I will end my talk by mentioning preliminary results in other regions (particularly Serpens and
Cepheus), as well as longer-terms prospects.