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Plenary Talks: Abstracts

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0001: String Theory

Authors: Brian Greene (Columbia University)

I will review the particular cosmological challenges--and cosmological opportunities--afforded by string theory, and discuss the recent progress that has been achieved.

0002: New Physics from Cosmic Acceleration

Authors: Georgi Dvali (New York University)

We discuss the motivations, observational constraints and consequences of modifying the fundamental laws of gravity at large distances. Such modifications can account for the observed late-time acceleration of the Universe, and can be differentiated from conventional dark energy via precision cosmology. They also lead to observably large perihelion precession of the Lunar and Martian orbits.

0003: CP Violation in Particle Physics and Cosmology

Authors: Helen Quinn (Stanford Linear Accelerator Center)

One of the great outstanding puzzles of particle cosmology is the question of how and when the imbalance between matter and antimatter developed. Sakharov told us that to develop such an imbalance requires three things: Baryon number changing processes; CP violation; and absence of thermal equilibrium for the relevant processes. Alternately the imbalance could be the consequence of an initial condition and an absolute conservation law that protects that condition. I will briefly review these conditions with emphasis on the two cases where CP violation occurs in our current particle physics theories and the conditions under which each of these two cases could produce the observed matter-antimatter imbalance. I will discuss the challenges for each scenario presented by our growing body of data on CP violation in B decays and masses and mixing in the neutrino sector.

0004: Inflation and the Standard Cosmological Model

Authors: Andrew R Liddle (University of Sussex)

I review the present observational status of inflationary cosmology, and critically review its role in the Standard Cosmological Model. I also consider how model selection statistics can define the Standard Cosmological Model from observational data.

0005: Modular and Brane Inflation in String Theory

Authors: Renata Kallosh (Stanford University)

Our universe is a unigue laboratory for testing string theory. However, until recently string theory did not allow us to describe inflation and the present stage of acceleration of the universe. We will describe the recent progress in string cosmology, which seems to resolve these problems. In particular, we will discuss KKLT construction of de Sitter vacua, which allows to describe acceleration of the universe, as well as several different models of string theory inflation. We will also describe the concept of string theory landscape and its implications for cosmology and for the theory of fundamental interactions.

0006: The Effect of Inhomogeneties on the Expansion Rate of the Universe

Authors: Antonio Riotto (INFN)

While the expansion rate of a homogeneous isotropic Universe is simply proportional to the square-root of the energy density, the expansion rate of an inhomogeneous Universe also depends on the nature of the density inhomogeneities generated during inflation. We show the scale of the Hubble radius is sensitive to the physical significance of the unknown spectrum of density perturbations beyond the Hubble radius.

0007: The Sloan Digital Sky Survey at Four

Authors: James Gunn (Princeton University)

The SDSS is entering its fifth (and nominally last) spring season. We have recently made public our third major data release, covering about 5200 square degrees of imaging, a half million spectra, and photometry for about 150 million objects. With reasonable weather this coming spring we may finish the imaging in the main survey area in the north galactic cap, but cannot finish the spectroscopy for the redshift survey. We and are currently seeking funds to finish this part of the survey as well as undertake a major new program in galactic structure and a search for intermediate-redshift supernovae. In this talk I will review the present state of the survey, its major scientific accomplishments, and the prospects for the future.

0008: Recent Results from WMAP

Authors: Lyman Page (Princeton University)

Measurements of the anisotropy in the cosmic microwave background (CMB) have given us the most stringent constraints on models of the birth and evolution of the Universe. We now have a standard model of cosmology that is consistent with, and draws upon, a wide variety cosmological observations. The model is based on the inflation paradigm and invokes "dark energy" to explain the observed acceleration and flatness of the universe. The current generation of CMB experiments is aimed at testing this rather provocative model. We review the latest results from the Wilkinson Microwave Anisotropy Probe (WMAP) and briefly discuss new directions in CMB research.

0009: The 2dFGRS and Large Cosmological Simulations

Authors: Carlos Frenk (University of Durham)

I will present new results from the now complete "2-degree field" redshift survey of 220000 galaxies (the 2dFGRS), focussing particularly on the final measurement of the galaxy power spectrum. I will also describe clustering results from the 10-billion particle "Millennium" N-body simulation and their comparison with the 2dFGRS results.

0010: SDSS, WMAP and the Early Universe

Authors: Max Tegmark (Massachusetts Institute of Technology)

I discuss the latest constraints from SDSS and WMAP on inflation models, in particular in the "landscape" context of a complicated potential with multiple minima.

0011: Studying Reionization Using Redshifted 21 cm Emission

Authors: Lars Hernquist (Harvard University)

I describe strategies for mapping out reionization using 21 cm fluctuations from high redshift gas. The reionization process will yield large ionized bubbles around galaxies and quasars that progress towards larger scales as the sources become brighter and more numerous and as small-scale HII regions merge. Projected onto the sky, 21 cm emission in various redshift slices will therefore yield patterns that evolve such that at early times the fluctuations between bright and dim regions will be mostly on small scales, but evolving towards larger ones as reionization progresses. Observations of the redshifted signal with frequency will measure the fluctuations as a function of frequency, making it possible to map out reionization in redshift. In detail, the expected signal is sensitive to how and when reionization occurred, and the nature of the sources producing the ionizing radiation. Ongoing and planned experiments to detect redshifted 21 cm emission will enable detailed measurements of this process and constrain early generations of star and galaxy formation in the Universe.

0012: The First Stars and their Impact on Cosmology

Authors: Volker Bromm (University of Texas at Austin)

How and when did the cosmic dark ages end? I review recent theoretical results on the formation of the first stars in the universe, and emphasize related open questions. I show how complementary observations, both at high redshifts and in our local cosmic neighborhood, can probe the first epoch of star formation.

0013: Exploring High Redshift Universe:Galaxies at the End of the Dark Ages

Authors: Andrew Bunker (Univeristy of Exeter, UK)

I will review recent progress in the study of distant galaxies. I will highlight the extension of the Lyman break technique to redshifts beyond z>4, and the powerful combination of HST imaging with ACS & NICMOS and ground-based spectroscopy. I will discuss the implications for reionization of recent measurements of the star formation history out to z~6.

0014: The Origin of Clusters and Large-Scale Structures: Panoramic View of the High-z Universe

Authors: Masami Ouchi (Space Telescope Science Institute)

We will report results of our on-going survey for proto-clusters and large-scale structures at z=3-6. We carried out very wide and deep optical imaging down to i=27 for a 1 deg^2 field of the Subaru/XMM Deep Field with 8.2m Subaru Telescope. We obtain maps of the Universe traced by ~1,000 Ly-a galaxies at z=3, 4, and 6 and by ~10,000 Lyman break galaxies at z=3-6. These cosmic maps have a transverse dimension of ~150 Mpc x 150 Mpc in comoving units at these redshifts, and provide us, for the first time, a panoramic view of the high-z Universe from the scales of galaxies, clusters to large-scale structures. Major results and implications will be presented in our talk. (Part of this work is subject to press embargo.)

0015: Observing Galaxy Evolution with the Great Observatories Origins Deep Survey

Authors: Mark Dickinson (NOAO)

The Great Observatories Origins Deep Survey (GOODS) is a multi-wavelength effort using the most powerful ground- and space-based telescopes to gather the deepest and best data in two regions of the sky. These data are serving as a public resource for studying the formation and evolution of galaxies and active galactic nuclei over a broad range of cosmic time. We have now nearly completed GOODS observations with the last of NASA's Great Observatories, the Spitzer Space Telescope, obtaining the deepest imaging taken with that facility at 3.6 to 24 microns. These data are a powerful new tool to study the formation and evolution of the stellar content in high redshift galaxies, as well as obscured energetics from star formation and active galactic nuclei, and I will present early results from the survey here.

0016: Probing the End of Dark Ages with High-Redshift Quasars

Authors: Xiaohui Fan (University of Arizona)

Studies of the highest redshift quasars probe the relation between the formation of the earliest supermassive black holes and galaxies. The quasar absorption lines trace the evolution of the intergalactic medium, and reveal when and how the reionization process happened, ending the cosmic dark ages. I will present recent results using the high-redshift quasar sample from the Sloan Digital Sky Survey (SDSS). More than 600 quasars at $z>4$ have been discovered in the SDSS, including sixteen at $z>5.7$, with the highest redshift of z=6.42. We show that the density of quasars decline rapidly towards high redshift. Meanwhile, their spectral properties show little evolution, indicating early chemical enrichment in the quasar environment. They also show strong signs of on-going star formation from their dust and gas emissions, suggesting the co-evolution of first generation black holes and galaxies. The absorption spectra of the highest-redshift quasars show strong evolution of Ly alpha optical depth at z>5.5. Complete Gunn-Peterson troughs have been detected in quasars at z>6.1. This indicates that the neutral fraction of the IGM begins to increase rapidly, and suggests that we might be reaching the tail end of the reionization process. The combination of the IGM measurements from SDSS quasars and CMB polarization measurements from WMAP can be used to probe the detailed history of reionization.

0017: The Role of Black Holes in Galaxy Formation

Authors: Karl Gebhardt (University of Texas)

Recent observational and theoretical work suggest that black holes are essential components of galaxies. In fact, they may be one of the keys to understanding how galaxies form and evolve. I will give a general overview of the observational results for black holes in galaxies, including discussion of their effects on the stellar orbital distribution. I will focus the talk on the two extreme mass ranges, from whether globular clusters contain black holes up to black holes in brightest cluster galaxies. The present results suggests that the black hole correlations span over seven orders of mass. This concordance suggests a more intimate connection between these different types of systems than what has previously been thought. I will also discuss the future of black hole studies, from space and from the ground.

0018: Constraining Dark Energy with the DEEP2 Survey

Authors: Marc Davis, Brian Gerke, Jeffrey A. Newman (University of California, Berkeley)

The DEEP2 redshift survey has now covered ~2.5 degrees^2 of sky and obtained nearly 40,000 spectra; the survey is more than two-thirds finished. We have used three-color imaging to efficiently select galaxies with magnitude R_{AB}<24.1 and redshifts in the range 0.7 < Z < 1.4. p < observations. Sunyaev-Zel?dovich of subject the be will and imaging ACS HST VLA, GALEX, Spitzer, Chandra, including data multiwavelength wide deep simultaneously combination unique a hosts which Strip, Groth Extended field, DEEP2 one in possible redshift high to clusters groups studies In-depth \sigma_8. measurement independent an Survey Sky Digital Sloan from z~0 distribution dispersion velocity both with combined if 0.2 ~ w \delta constraint leading survey, full counted sizable ~250 total that are indications preliminary work, does method indicate simulations catalogs mock tests early Studies w. on depends each z~1, at structure growth element volume probe we dispersion, internal their function as space find virialized number counting By Energy, Dark parameter state equation constraints set can by here describe We>

0019: Kinematics and Dark Energy from Supernovae at z>1

Authors: Adam Riess (Space Telescope Science Institute (STScI))

Type Ia supernovae (SNe~Ia) provide the only direct evidence for an accelerating universe and the existence of dark energy. We are in the third year of the first space-based search and follow-up campaign SNe Ia at z>1 using ACS and NICMOS on the Hubble Space Telescope to further explore the kinematics of the expanding Universe and to characterize the nature of dark energy.

0020: Current Progress and Problems in Modeling Type Ia Supernovae

Authors: Alexei M. Khokhlov (University of Chicago)

Recent results of three-dimensional modeling of thermonuclear Type Ia supernova explosions predict significant deviations of the explosion from spherical symmetry. The level of deviations depend on initial conditions at ignition and on the mode of explosion (deflagration or detonation). Theoretical models predict varying strength of the explosion and various degree of mixing of chemical elements in supernova ejecta. Some of the theoretical predictions seem to contradict observations of Type Ia's. A significant gap exists now between the current three-dimensional models and observations of Type Ia's.

0021: The Cosmic X-ray Background

Authors: Guenther Hasinger (MPE Garching)

The majority of the cosmic X-ray background has been resolved in deep Chandra and XMM-Newton Surveys into discrete sources. By studying their redshift distribution we can infer the accretion history of black holes in the Universe. There is a clear anti-hierarchical growth, with massive black holes growing early in the Universe into powerful Quasars and lower-mass, less luminous AGN coming significantly later.

0022: X-Ray Emission from Clusters of Galaxies: Latest Developments

Authors: Andrew Fabian (University of Cambridge)

Significant progress has been made a) in the use of clusters as cosmological probes and b) in demonstrating the roles of heating and cooling of dense intracluster gas. a) The baryon fraction in clusters, which is well-measured directly with X-ray observations, should be constant with cosmic epoch and so can be used to measure cluster distance. This gives a determination of the cosmological constant Lambda which is independent of, and complementary to, the supernova and cosmic microwave background measurements. Combining all results gives strong constraints on the properties of Dark Energy. b) The denser gas in the cores of clusters often has cosmologically short radiative cooling times and temperatures decreasing to the centre yet does not appear to be cooling, presumably because of a compensating heat input. Heating of this gas, including by damping of sound waves produced by the central radio source, will be discussed as will its relevance to the formation of massive galaxies.

0023: Cosmological Weak Lensing

Authors: A. Refregier (CEA/Saclay)

Weak lensing provides a unique measure of the distribution of mass in the universe and of cosmological parameters. After describing the principles of weak lensing, I will review the observational status and cosmological implications of current weak lensing surveys. I will then present future weak lensing surveys and instruments, and show how they will constrain cosmology beyond the concordance model. I will also describe the technical challenges that have to be met for the potential of weak lensing to be fully realized.

0024: Cosmology with the Sunyaev-Zel'dovich Effect

Authors: John Carlstrom (KICP)

The Sunyaev-Zel'dovich effect (SZE) provides a unique way to map the large scale structure of the universe as traced by massive clusters of galaxies. As a spectral distortion of the cosmic microwave background, the SZE is insensitive to the redshift of the galaxy cluster, making it well-suited for studies of clusters at all redshifts, and especially at reasonably high redshifts, (z > 1) where the abundance of clusters is critically dependent on the underlying cosmology. Recent high signal-to-noise detections of the SZE have enabled interesting constraints on the Hubble constant and the matter density of the universe using small samples of galaxy clusters. Upcoming SZE surveys are expected to find hundreds to tens of thousands of new galaxy clusters, with a mass selection function that is remarkably uniform with redshift. The current observations will be reviewed briefly, but the emphasis will be on new SZE instruments underway that will conduct large untargeted surveys for clusters such as AMI, SZA, APEX-SZ, ACT and SPT. I will review the cosmology that can, in principle, be investigated with the upcoming SZE surveys and the observational and theoretical challenges which must be met before precise cosmological constraints can be extracted from the survey yields.

0025: The Galactic Center Black Hole and the Central Star Cluster

Authors: Reinhard Genzel (Max-Planck-Institut fuer Extraterrestrische Physik)

I will discuss recent observations, employing adaptive optics imaging on large ground-based telescopes that prove the existence of a massive Black Hole in the center of our Milky Way, beyond any reasonable doubt. These observations also provide evidence that the Galactic Center Black Hole may be rotating rapidly. I will also discuss the unusual properties of the nuclear star cluster. Young massive stars formed a few million of years ago appear to be located in two, counter-rotating disks. Some massive stars are found within the central light day. Possible formation scenarios will be mentioned.

0026: Relativistic Jets from Evolving Accretion Discs

Authors: Rob Fender (University of Southampton)

I will review our recent empirically-based understanding of the coupling between accretion flows and jets in accreting black hole systems. Based on a large collection of multiwavelength observations of black hole X-ray binary systems, we have developed a simple model for explaining the different types of jets observed from such systems, and their coupling to the accretion flow. The model is based upon the scaling of jet power and Lorentz factor with disc state, and the internal shocks which are inevitably formed when the jet speed increases. Furthermore, a comparison is made with the disc-jet coupling observed in Active Galactic Nuclei, testing the hypothesis that black hole accretion is essentially scale-free.

0027: Chandra Observations of Relativistic AGN Jets

Authors: Dan Schwartz (Harvard-Smithsonian Center for Astrophysics)

We review Chandra observations of arcsecond scale radio jets in quasars and powerful radio galaxies. There are close correlations of X-ray and radio brightness, but also significant differences. The radio/optical/X-ray spectral energy distributions typically do not allow a simple synchrotron model to produce the entire radiation spectrum. Assuming minimum energy density, we can explain the X-ray emission as inverse Compton scattering on the cosmic microwave background (CMB), and deduce that the jets are moving with bulk Lorentz factors of 3--10 on scales 100's of kpc from the central quasar. The power carried by these jets imply they play a critical role in the accretion onto the central black hole, and should profoundly influence their environment; e.g., by retarding cooling flows in clusters of galaxies. If inverse Compton scattering on the microwave background is producing X-rays in nearby jets such as 3C 273, then intrinsically similar objects must be seen with the same surface brightness out to redshifts at which they first form.

0028: Outflows from Black Hole Accretion

Authors: Mitchell C. Begelman (JILA, University of Colorado)

It appears that black holes can be fussy eaters, swallowing only a fraction of the matter available to them. I will discuss the reasons for this curious behavior, and recent work on the outflows that result.

0029: AGN Jets and Their Connection with Accretion: a Phenomenological View

Authors: Annalisa Celotti (S.I.S.S.A.)

The talk will focus on some of the recent observational findings and developments in the modeling of radio-loud AGN, concerning both their non-thermal emission and the connection between jets and the accretion properties.

0030: Numerical MHD Models of Accretion Flows

Authors: Jim Stone (Princeton University)

Progress and results from numerical MHD simulations of accretion flows onto compact objects will be reviewed. In particular, the global structure and properties of accretion flows onto rotating black holes studied with fully GR MHD simulations, and the dynamics and structure of radiation dominated disks revealed by radiation MHD simulations, will be highlighted. The challenges involved in computing realistic synthetic spectra from current simulations will be discussed, as well as directions for future development.

0031: Gamma-Ray Bursts and X-Ray Flashes: New Insights from the HETE Mission

Authors: George R. Ricker (Massachusetts Institute of Technology)

The High Energy Transient Explorer (HETE) has observed more than 400 gamma-ray bursts (GRBs) in 4 years of operations. It is currently localizing 20 - 25 GRBs per year, and had accurately localized 74 GRBs as of early October 2004. Twenty-eight of these localizations have led to the detection of X-ray, optical, or radio afterglows; 15 of the bursts with afterglows have redshift determinations. Rapid X-ray, optical, IR, and radio follow-up identifications of HETE GRBs are revealing the nature of "dark bursts" and X-ray flashes (XRFs), and have firmly established the GRB-supernova connection as a result of HETE's discovery of GRB030329 (=SN2003dh). Follow up observations of HETE bursts have proven to be extremely productive in relating GRBs to their progenitors, to their local ISM, and to their host galaxies. Results from recent HETE observations will be presented, with special emphasis on the implications for GRBs with very low (z < 0.5) or very high (z > 5) redshifts, and the complementarity and anticipated synergy between HETE and Swift. The HETE scientific team includes participants from France, Japan, Brazil, India, Italy, and the USA.

0032: The Enigmatic Gamma-Ray Bursts: A Mystery Being Solved

Authors: Pawan Kumar

Flashes of radiation in gamma-rays are observed once or twice a day originating from some random part of the sky (and random in time). These events (explosions) typically last for less than a minute. During this time the energy radiated in gamma-rays is of order 10^{51} erg or the kinetic energy release in a typical supernova explosion but about two orders of magnitude larger than the EM-radiation from a supernova in a month. Multi-wavelength observations of radiation we receive following Gamma-ray bursts have greatly advanced our understanding of these enigmatic explosions. For instance, we now know that gamma-ray bursts are highly beamed and relativistic explosions. In the last few years we have seen a number of compelling lines of evidence that at least a certain fraction of gamma-ray bursts are associated with the death of massive stars. I will describe recent observations and discuss what we have learned about these bursts. The nature of the underlying object and the currently unsolved problems will also be described.

0033: Relativistic Explosions

Authors: Andrew MacFadyen (Institute for Advanced Study)

Recent numerical work on multidimensional relativistic outflows relevant to GRB afterglow observations are presented. Special relativistic hydrodynamical simulations using adaptive mesh refinement (AMR) allow for resolving the multidimensional dynamics of GRB blast waves. We present models of jetted relativistic blast waves making the transition to non-relativistic flow.

0034: Observations of Soft Gamma Repeaters

Authors: Chryssa Kouveliotou (NASA Marshall Space Flight Center)

Magnetars (Soft Gamma Repeaters and Anomalous X-ray Pulsars) are a subclass of neutron stars characterized by their recurrent X-ray bursts. While in an active (bursting) state (lasting anywhere between days and years), they are emitting hundreds of predominantly soft (kT=30 keV), short (0.1-100 ms long) events. Their quiescent source X-ray light curves exhibit pulsations in the narrow range of 5-11 s; estimates of these rotational period rate changes (spin-down) indicate that their magnetic fields are extremely high, of the order of 10^14-10^15 G. Such high B-field objects, dubbed "magnetars", had been predicted to exist in 1992, but the first concrete observational evidence were obtained in 1998 for two of these sources. I will discuss here the history of Soft Gamma Repeaters, and their spectral, timing and flux characteristics both in the persistent and their burst emission.

0035: (Anomalous) X-ray Pulsars

Authors: V. M. Kaspi (McGill University)

I review the observational status of the exotic class of young neutron stars known as "Anomalous X-Ray Pulsars," emphasizing the most recent discoveries, including short X-ray bursts, long-lived X-ray flares, and correlated IR/X-ray emission. I will explain why the favoured model to explain the unusual properties of these sources is that they are "magnetars," that is, their emission is powered by the decay of enormous magnetic fields.

0036: Magnetars: Plasma and Vacuum

Authors: Jeremy S. Heyl (University of British Columbia), Lars Hernquist (Harvard-Smithsonian Center for Astrophysics), Ryan Shannon (University of British Columbia/Cornell U.)

Electromagnetic radiation travelling through the magnetosphere of a neutron star interacts with both with the plamsa magneto-hydrodynamically and with the vacuum quantum-electrodynamically. These processes working in concert provides a model for the formation of pair fireballs in soft-gamma repeaters. These processes working in conflict provides a unique method to probe the properties of the plasma surrounding neutron stars.

0037: Millisecond Pulsars & Gravitation

Authors: Richard N. Manchester (Australia Telescope National Facility)

Millisecond pulsars have pulse periods of less than a few tens of milliseconds and very small spin-down rates, probably as a result of mass-accretion in an earlier stage of evolution, and are extraordinarily stable clocks. Most of them are in binary orbit with another star, with orbital periods ranging from 1.5 hours to hundreds of days. Recent pulsar searches, especially those using the multibeam receiver at Parkes, have discovered many millisecond pulsars, both in globular clusters and in the Galactic disk. Seven or eight of these, including the unique double-pulsar system PSR J0737-3039A/B, have short orbital periods and massive companions, probably neutron-stars, and have orbital velocities which are a significant fraction of the velocity of light. These systems provide unrivalled opportunities for testing theories of gravitation in the strong-field regime. Other millisecond pulsars with long orbital periods and low-mass companions allow tests of equivalence principles. Millisecond pulsars in globular clusters allow exploration of the cluster gravitational potential and give evidence for high mass-to-light ratios for the cluster core. Long-term precision timing of a large sample of millisecond pulsars, the so-called pulsar timing array, has the potential to make a direct detection of gravity waves. Such an array is sensitive to gravity waves in the nanoHertz frequency regime and hence complements other existing and planned detectors.

0038: Testing GR with the Double Pulsar: Recent Results

Authors: Michael Kramer (University of Manchester for the PHSURVEY team)

The recently discovered double pulsar system is the most wonderful system to study relativistic gravity in the strong field limit. The possibility to measure two clocks orbiting each other in a strong gravitational field allows tests of GR and other theories of gravity that have not been possible before. This talk will report on the achieved tests and will focus on the most recent results.

0039: Binary Pulsars and Strong-Field Tests of General Relativity

Authors: Thibault Damour (Institut des Hautes Etudes Scientifiques)

A review will be given of the constraints imposed by binary-pulsar data on gravity theories. We focus on "tensor scalar" theories, which are the best motivated alternatives to General Relativity. Contrary to solar-system tests, binary-pulsar experiments allow one to test non-perturbative strong-field aspects of relativistic gravity. In addition, they test some of the radiative aspects of gravity. Present binary-pulsar data are all in impressive agreement with the predictions of General Relativity, and leave very little room for the possible existence of long-range deviations from Einstein's gravity. This confirms that General Relativity is an accurate description of the fully nonlinear, and time-dependent, regime of relativistic gravity, and can be trustfully used to describe black holes and gravitational waves.

0040: Pulsar Emission: Is It All Relative?

Authors: Alice K. Harding (NASA Goddard Flight Center)

Thirty-five years after the discovery of pulsars, we still do not understand the fundamentals of their pulsed emission at any wavelength. The fact that even detailed pulse profiles cannot identify the origin of the emission in a magnetosphere that extends from the neutron star surface to plasma moving at relativistic speeds near the light cylinder compounds the problem. I will discuss the role of special and general relativistic effects on pulsar emission, from inertial frame-dragging near the stellar surface to aberration, time-of-flight and retardation of the magnetic field near the light cylinder. Understanding how these effects determine what we observe at different wavelengths is critical to unraveling the emission physics.

0041: Thermal Radiation from Neutron Stars

Authors: George Pavlov (Pennsylvania State University)

Thanks to the outstanding capabilities of Chandra, XMM-Newton and HST, thermal radiation from about 20 isolated neutron stars has been observed in soft X-rays and UV-optical. I will discuss the results of recent observations of thermal radiation from active pulsars and radio-quiet isolated neutron stars. Such observations allow one to measure the surface temperatures, radii and masses of neutron stars, constraining the properties of the superdense matter in their interiors.

0042: Neutron Stars as a Probe of the Equation of State

Authors: James M. Lattimer(Stony Brook University)

Observations of neutron stars are leading to a wide variety of constraints on the underlying dense matter equation of state. Recent and proposed observations include dynamical masses from radio binary pulsars and accreting neutron stars in X-ray binaries, radiation radii, temperatures and ages from cooling neutron stars, redshifts and radiation radii from X-ray bursters, and moments of inertia from supernova remnants and relativistic binaries. Analytic solutions of Einstein's equations provide a useful guide to the interpretation of observations in some cases. From the other end of the spectrum, complementary constraints on dense matter equations of state exist from laboratory experiments, and implications of proposed laboratory experiments, such as the PREX experiment to accurately measure the neutron skin thickness of lead, will be discussed.

0043: Very High Energy Gamma Rays and Origin of Cosmic Rays

Authors: Felix Aharonian (Max-Planck-Institut fuer Kernphysik)

I will highlight the recent exciting discoveries of TeV gamma-rays from supernova remnants, pulsar-driven nebulae, Galactic Center, blazars, etc., and discuss astrophysical implications of these results with an emphasis on two topical issues - origin of galactic and extragalactic cosmic rays and physics of relativistic winds and jets. I will argue that with arrival of GLAST and the new generation of Imaging Atmospheric Cherenkov Telescope Arrays, gamma-ray astronomy will provide a key contribution in the solution of the century-old problem of origin of Cosmic Rays.

0044: The Status of Theoretical and Observational Work on Ultra High Energy Cosmic Rays

Authors: Alan Watson (University of Leeds)

Cosmic rays with energies above 100 EeV almost certainly exist but their flux, origin and nature are all uncertain. Theoretical explanations, many of which make the assumption that the highest energy particles are protons, will be reviewed although the limited evidence relating to mass composition is far from clear cut. The present status of the observational scene will be described with particular attention given to the energy spectrum and to the reports of clustering of arrival directions. Finally, the progress and prospects of the Pierre Auger Observatory will be outlined.

0045: Particle Acceleration in Relativistic Flows

Authors: John Kirk (Max-Planck-Institut fuer Kernphysik)

A common property shared by different astrophysical sources of TeV gamma-rays is the presence of bulk motion at relativistic speed. The intrinsic spectra of the nonthermal radiating particles in these sources also show interesting similarities. I will present recent work suggesting that two distinct acceleration mechanisms could be at work: the stochastic first-order Fermi process at shocks, together with non-stochastic acceleration in the induced electric field of a relativistic current sheet.

0046: Underground Searches for Cold Relics of the Early Universe

Authors: Laura Baudis (University of Florida)

We have strong evidence on all cosmic scales, from galaxies to the largest structures ever observed, that there is more matter in the universe than we can see. Galaxies and clusters would fly apart unless they would be held together by material which we call dark, because it does not emit electromagnetic radiation. Although the amount of dark matter and its distribution are fairly well established, we are clueless regarding its composition. Leading candidates are Weakly Interacting Massive Particles (WIMPs), which are 'cold' thermal relics of the Big Bang, ie moving non-relativistically at the time of structure formation. An example is the neutralino, or the lightest supersymmetric particle, which arises naturally in supersymmetric extensions of the Standard Model of particle physics and has a typical mass of about 100 GeV. Neutralinos can interact via elastic scattering with nuclei in an ultra low background terrestrial detector. After a general introduction to dark matter and its detection methods, I will present current results of direct detection experiments, with emphasis on the Cryogenic Dark Matter Search (CDMS), which uses phonon and ionization mediated Ge and Si detectors operated below 50 mK to detect the energy deposited by a recoiling nucleus. I will show first results from operating 12 CDMS detectors at the Soudan Undeground Lab in northern Minnesota, and discuss the prospects to detect WIMPs in the near future. In the last part of my talk I will address the far future: which sensitivities are needed in order to test a large part of the predicted parameter space and what are the proposed experimental techniques that will allow to reach them?

0047: Neutrino Oscillation Experiments

Authors: Andreas Piepke (University of Alabama)

Experiments searching for neutrino oscillations yield strong evidence for the existence of non-zero neutrino masses and large flavor mixing in the Lepton sector. A picture of the neutrino mixing matrix is starting to emerge. The key results supporting this claim will be discussed, along with new projects being set up to clarify the remaining questions.

0048: Neutrinos and the Cosmos

Authors: Hitoshi Murayama (University of California, Berkeley)

I will discuss the intimate connections among neutrino oscillation physics, cosmology, and particle physics, including the baryon asymmetry of the universe.

0049: Theoretical View

Authors: R. Kolb

Visions of the Future talk

0050: Experimental View

Authors: S. Khan

Visions of the Future talk