WORKSHOPS - SUMMER 2007

* denotes the organizer responsible for participant diversity in the workshop

May 28 – June 10
Cytoskeletal Assembly and Cellular Motility

Organizers: A. Carlsson, L. Edelstein-Keshet*, J. Tang, Y-L. Wang

This workshop will address the key physical events in cell motility, including cell migration, cell division, and intracellular transport, as well as  the response of cells to external cues. It will focus on three major areas: the physical properties of cellular structure, the generation of mechanical forces and the coordination involved in motile events, and the mechanisms that determine the behavior of cells in the presence of physicochemical stimuli. Topics to be treated in these areas include actin-based motility, cell crawling on flexible substrates, whole-cell treatment of motion microtubule assembly as it relates to cell division, and cellular signaling networks.


May 28 – June 10
Neutrino Physics: Looking Forward

Organizers: V. Barger, G. Gelmini, D. Marfatia*, J. Valle

Despite the rapid progress in the physics of massive neutrinos, our knowledge of the neutrino sector is incomplete. This data-oriented workshop will focus on the major areas of neutrino physics with an eye to the future: (a) results from MiniBooNE, (b) T2K and future long-baseline exploration, (c) neutrinoless double beta decay, (d) neutrino astrophysics and cosmology and (e) model-building to elucidate the origin of neutrino masses and mixings. We intend to bring together a diverse group of physicists including experimentalists, phenomenologists, cosmologists, astrophysicists, and model-builders.

 


June 4 – 17
Implications of Swift's Discoveries About Gamma –Ray Bursts

Organizers: N. Gehrels, D. Lamb*, L. Piro

Observations of gamma-ray bursts (GRBs) made possible by Swift have answered important questions about GRBs and raised many more.  The purpose of the workshop will be to (1) assess our understanding of GRBs in the light of the discoveries that Swift has made, (2) understand the implications of these discoveries for the nature of GRBs and for their use as tools to probe the universe, including the properties of the very high redshift universe and the nature of dark energy, and (3) identify the most important questions for future study. Topics that the workshop will address include the following:

 o The GRB/supernova connection;

 o The nature of short GRBs and their redshift distribution;

 o Implications of X-ray observations for the nature of GRBs and their afterglows;   

o The nature of GRB jets, as implied by Swift XRT observations of GRB afterglows;

 o Evidence of long-lived central engines in short and long GRBs and the implications for the nature of the central engines

 o Implications of the abundances of heavy elements in the circumburst environment, the host galaxies of GRBs, and DLAs    along the line of sight from the bursts to us, as inferred from high resolution optical spectra of GRB afterglows;

 o GRBs as probes of the missing baryon mass in the local (z < 1) universe and of the very high redshift (z > 5) universe; and

 o The use of short GRBs as "standard sirens" and long GRBs as "standard candles" to constrain the properties of dark energy.


June 11 - July 1
Notions of Locomotion

Organizers: A. Hosoi, G. Huber, T. Powers*, M. Shelley

Locomotion as a phenomenon in the biological world has long captured the imagination of physical scientists.  Da Vinci's studies on gliding and the role of vortices in bird flight are prominent early examples.  In modern times, the physicist's fascination with Nature's ingenious solutions continues unabated. With the emergence of physical biology, the study of propulsion from the molecular to the macroscopic scale promises to be an area of intense activity for the foreseeable future. Shouldn't the physics be simple?  After all, at its most basic level, locomotion of organisms is made possible by Newton's Third Law: For every action there is an equal and opposite reaction.  The fins of a swimming fish accelerate fluid elements backwards, which, in turn, push the fish forwards.  A snail secretes a thin film of complex viscous fluid and crawls by generating stresses in this fluid. The rotation of a bundle of helical bacterial flagella is resisted by viscous drag, which also provides the thrust to push the cell body forward. Close inspection of these examples reveals a complex interaction between the fluid media and the deformable propulsive elements, leading to challenging physical questions. In many cases, simple-sounding questions are still unanswered: How are movements of the locomotor and medium organized in space and time?  What is the role of the medium's elastic nature?  What if the organism changes its shape in response to the medium?  These questions lie at a unique intersection of diverse fields, including field theory, many-body theory, fluid mechanics, solid mechanics, bioengineering, applied mathematics, and cell and organismal biology.  To tackle these questions requires a cross-disciplinary approach, and we aim to bring together researchers from these different disciplines and facilitate new collaborations that would not otherwise be easy to establish.


June 11 - July 1
Modeling Galaxy Clustering

Organizers: A. Berlind, J. Cohn*, M.White, I. Zehavi

The past few years have seen an explosion in the amount of data we have on galaxy clustering and its evolution, which has led to new and powerful methods for modelling and describing the data. This meeting will get theorists, modelers, phenomenologists and observers together to compare and extend the existing modelling methods, to identify physical processes underlying the successes of the models, to maximize the utility of current observations and to optimize future ones.

 


June 18 - July 1
Supernovae as Cosmological Distance Indicators

Organizers: W. Freedman, J. Frieman*, A. Khoklov

Major surveys are now underway, and more ambitious ones are planned, to use large numbers of supernovae to measure cosmic distances to probe the dark energy. For these measurements to bear fruit, better understanding of the systematics of supernova distance estimates will need to be achieved. This workshop will overview the latest results from on-going supernova surveys, critically assess the progress that has been made in quantifying systematics, and explore the prospects and pathways for better controlling them in the future. In the process, we plan to compare the different methods of inferring distances from SN light curve data and identify potential new analysis methods that may be more optimal and/or robust. The workshop also aims to foster dialogue between observers and theorists working on modeling supernova explosions and observables, with the goal of addressing how supernova theory can or should inform supernova distance estimates.


July 2 – 22
Topological Phases and Applications to Quantum Information Processing

Organizers: J. Eisenstein, M. Freedman, K. Shtengel*, S. Simon

Topological phases of matter expected to exist in strongly correlated systems have become a subject of much attention recently, both from theorists and experimentalists. In two spatial dimensions, excitations in these phases may be characterized by braiding (nonabelian) statistics which make them very attractive candidates for fault-tolerant quantum computation and, in particular, topological quantum computation. The goal of this workshop is to both study the physical nature of topological phases as well as to address the most important theoretical issues connected with any attempt to practically realize a topological quantum computer. The proposed workshop is designed to bring together experts from diverse fields of physics and mathematics. The exchange of ideas between researchers working on these subjects will hopefully result in making new inroads into this broad, inter-disciplinary field.


July 2 – 29
String Theory and Quantum Geometry

Organizers: R. Dijkgraaf, D. Freed*, H. Oguri, T. Pantev

In recent years the collaboration of string theorists and mathematicians has been very fruitful. Many deep result in supersymmetric gauge theories, topological strings, M-theory, and nonperturbative string theory on the physics side---and algebraic geometry, symplectic topology and category theory on the mathematics side---have been obtained as a direct result of the joint efforts of physicists and mathematicians.  There are new interactions stemming from the link between gauge theories and the geometric Langlands program.  The workshop will nurture collaborations between physicists and mathematicians while at the same time aim at developing tools to address physical questions in string phenomenology and cosmology.


July 23 – August 13
Jamming

Organizers: A. Liu, N. Menon*, E. Weeks

Jamming occurs when a system with no quenched disorder changes from an ergodic and mobile state to an immobile and solid-like yet disordered state.  Jamming transitions can be induced in a variety of systems by tuning different control parameters. Examples include supercooled liquids that become glasses as temperature is lowered below the glass transition temperature, flowing granular materials that become static granular packings as the shear stress is decreased below the yield stress, and colloidal suspensions that become colloidal glasses as the density is increased near random close packing.  These systems display common behavior near the jamming transition, such as extremely long relaxation times, cooperative dynamics with large spatial correlations, lack of obvious structural changes at the transition, and locally anisotropic and nonlinear responses to perturbations.  Despite these similarities, it is still an open question whether a unified description of jamming in these diverse systems is possible.  This workshop will bring together people interested in jamming in glassforming liquids, glasses,  granular media, and soft materials such as foams, colloids, and gels, as well as people working on rigidity percolation and bootstrap/k-core percolation.

 


July 30 – Sept. 2
Novel Aspects of Superconductivity

Organizers: A. Chubukov*, P. Coleman, P. Lee, D. Morr

In this workshop, we plan to focus on the new physics of superconductivity in strongly correlated systems. Many strongly correlated electron materials, such as the Ce-based heavy fermion systems, cuprates, cobaltates, quasi one-dimensional and quasi two-dimensional organic charge transfer salts become unconventional superconductors at low temperatures. The origin of superconductivity in most of these systems cannot be explained using the conventional Bardeen-Froehlich idea of phonon-mediated pairing of fermions, but is rather (most likely) due to a strong electron-electron interaction. While some researchers believe that the key physics behind an electronic pairing mechanism is the proximity to a Mott insulator, others propose that it is the proximity to a quantum critical point that gives rise to unconventional superconductivity. This topic is a very exciting area of theoretical and experimental research with a large number of new results, concepts and unexpected connections between the physical behavior exhibited by different families of materials.

Specifically, this workshop will address the following issues:
1) Quantum criticality: a curse or a blessing for superconductivity?;
2) Resonant superfluidity of fermionic atomic gases;
3) Superconductivity vs.~Mott physics and spin liquid physics in the cuprates, heavy fermion and organic materials: are Mott insulators and superconductors relatives?;
4) Pairing of ill defined electrons; how incoherent can fermions be to still allow Cooper pairing?;
5) Itinerant vs. localized aspects of the pairing near quantum-critical points in heavy-fermion and other systems;
6) unconventional superconductivity in finite size systems: a new path to understanding strongly correlated systems on the local scale;
7) relations between pairing in condensed-matter systems and color superconductivity in quark matter.

For current information, please see: http://novelsc.blogspot.com


August 13 – Sept. 2
Systems Biology of Infectious Diseases

Organizers: D. Burke, C. DeLisi*, S. Levin, A. Levine

The mathematical sciences have long spurred fundamental and applied advances in the life sciences. In the modern era a number of major transformations are associated with specific  individuals:  the profound physiological analyses of Helmholtz, and  the Crick theory of X-ray scattering from double helices, are only two among many.   More recently  a major cultural shift toward mathematics and computation has been forced by the Human Genome Project which would not have been possible, absent the methods of mathematics and advanced computation.

The subject on which  this workshop focuses, infectious disease, is among the areas in which applied and fundamental quantitative science has played a major role for decades. Contributions range from differential equations models of disease dynamics in human populations--which provides, among other things,   the basis for policy--to the quantitative tools of the civil engineer, which have increased life span by decades.  More recently, advances in cell biology have transformed our understanding of disease related processes, including molecular changes that occur when pathogens infect cells; physical processes that underlie infection; and systemic changes in the host. We are now poised to understand the biological, chemical and physical determinants of host-to host transmission and changes in host range, and to begin integrating such understanding with changes in demographics, climate, globalization and so on.   A central goal of infectious disease research is, therefore, integration across scales.  This workshop offers a unique opportunity for physicists to exchange ideas with colleagues in the biomedical sciences on a range of topics relevant to emerging and remerging infectious disease, which cut across scales. These include the physical properties of proteins and nucleic acids and their interactions;   the mechanisms governing the behavior of molecular motors; the physics of transcriptional and translational control; learning, memory and adaptation in cells, organs and individuals; and the dynamics of host-host and host parasite interactions.

 


August 13 – Sept. 2
Between the LHC and B Factories

Organizers: Y. Grossman*, Z. Ligeti, G. Perez, M. Schmaltz

Flavor and electroweak physics have been the subject of intense experimental and theoretical progress. At present, all data is in agreement with the standard model. This situation may change dramatically when the LHC starts searching for TeV scale particles next year. In addition, the LHC experiments will study unparalleled samples of top and bottom quarks, thereby beginning a new era of precision top-flavor physics. By jointly analyzing different types of data: LHC particle spectra, precision flavor and electroweak data, and dark matter abundances we are likely to learn significantly more than from one experiment alone. We expect this to be a lively and useful workshop where participants interested in quark and lepton flavor physics with special emphasis on the third generation interact with experts on models of new physics at the TeV scale.


For more information about Aspen, call (970) 925-2585.