Browsing by Subject "FTPI"

Now showing 1 - 20 of 572
  • Thumbnail Image
    Item
    30 years quantum Hall effect
    (2010-04-30) von Klitzing, Klaus
  • Thumbnail Image
    Item
    3D Quivers and Integrability
    (2013-06-11) Koroteev
  • Thumbnail Image
    Item
    4 \pi in the sky
    (2017-05) Kaloper, Nemanja
    I will talk about EFT of monodromy inflation, strong coupling effects and their implications for future searches for primordial gravity waves.
  • Thumbnail Image
    Item
    Abundance Constraints on Early Chemical Evolution
    (2012-07-23) Truran, Jim
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Active gels: towards a physical description of the cytoskeleton
    (2012-07-30) Joanny, Jean-Francois
  • Thumbnail Image
    Item
    AF Spin Gap Limits the Coherent SC Gap in Cuprates
    (2018-05) Tranquada, John
    We have performed inelastic neutron scattering measurements of the magnetic excitations in La(2-x)Sr(x)CuO(4) at doping levels on both sides of the putative quantum critical point, in both the superconducting and normal states. The low-energy excitations look similar at both dopings: there is a peak in the magnetic spectral weight at 15-20 meV, and the spin gap (~ 7 meV) in the superconducting state develops on the low-energy side of this peak. Past work in a magnetic field indicates that suppressing the superconducting order only causes the spin gap to fill in—there is no evidence of critical behavior of the peak in spectral weight. I will discuss this result in the broader context of magnetic correlations in the cuprates.
  • Thumbnail Image
    Item
    Aggregation and folding phase transitions of RNA molecule
    (2012-07-30) Bundschuh, Ralf
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    All order linearised hydrodynamics from fluid-gravity correspondence
    (2016-05-14) Lublinsky, Michael
    Relativistic fluid dynamics emerges as an effective theory describing strongly coupled QFTs at finite temperature. Following a brief intro into relativistic fluid dynamics, I will discuss how constitutive relation/transport coefficients of a fluid can be obtained using the holographic methods. Applying the fluid/gravity correspondence, we have determined the (linearized) stress energy tensor of N=4 super-Yang-Mills theory at strong coupling accounting for all orders in derivatives of the fluid velocity. I will introduce momenta-dependent transport functions, such as generalized shear viscosity, and will derive closed form linear holographic RG|flow-type equations for these functions.
  • Thumbnail Image
    Item
    Alpha-attractors and B-mode targets
    (2017-05) Kallosh, Renata
    We discuss alpha-attractor cosmological models which can be derived by a consistent reduction from theories with maximal supersymmetry, like M-theory, superstring theory, or maximal supergravity, to minimal supersymmetry models. These models provide a set of targets for the future detectors of primordial gravitational waves, scanning the region of tensor to scalar ratio between 1/100 and 1/1000.
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Anomalous magnetic moment of a bound electron
    (2016-05-12) CZARNECKI, ANDRZEJ
    The mass of the electron is best determined with hydrogen-like ions in|a Penning trap. Binding in an ion removes the error due to the thermal|motion of the electron. However, the price is that some properties of|the electron are modified by the binding. These changes can be|computed in QED but there are interesting complications due to the|binding. I will present a new determination of the g-factor of a bound|electron. This calculation is motivated by the 2014 improvement in the|mass of the electron and makes further experimental progress|possible. Bound-state studies have traditionally been a mix of art and|science, and part of our motivation is to make them more algorithmic.
  • Thumbnail Image
    Item
    Anomalous transport proper.es of SrTiO3 (STO) accumula.on layers
    (2018-05) Fu, Han
    In this talk, we study the low temperature conductivity of electron accumulation layers induced by the very strong electric field at the surface of STO sample. Due to the strongly nonlinear lattice dielectric response, the three-dimensional density of electrons n(z) in such a layer decays with the distance from the surface z very slowly as n(z)~1/z^{12/7}. We show that when the mobility is limited by the surface scattering, the contribution of such a tail to the conductivity diverges at large z because of growing time electrons need to reach the surface. We explore truncation of this divergence by the finite sample width, by the bulk scattering rate, or by the crossover to the bulk linear dielectric response with the dielectric constant \kappa. As a result we arrive at the anomalously large mobility, which depends not only on the rate of the surface scattering, but also on the physics of truncation. Similar anomalous behavior is found for the Hall factor, the magnetoresistance, and the thermopower.
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Antimatter cosmic rays: recent results with the semi-analytic approach
    (2017-05) Salati, Pierre
    The nature of dark matter, an essential component of the Universe, is still unresolved. The best candidate is a weakly interacting particle yet to be discovered at accelerators. In most models, these exotic species annihilate and yield in particular antiprotons and positrons, hence the connection between the dark matter problem and antimatter cosmic rays. Distortions and anomalies in the antiproton and positron spectra are actively searched. A positron excess has actually been discovered and recently confirmed. But claiming that dark matter species have been discovered in the cosmic radiation requires to understand it and to properly model the various backgrounds in which the signal might be found. To achieve this goal, a key ingredient is the transport of charged particles within the magnetic halo of the Milky Way. In this talk, I will focus on a few (semi)-analytic methods used to solve the transport of cosmic rays and derive their fluxes at the Earth. I will then describe the so-called pinching method, which allows for a fast and reliable calculation of the positron spectrum even at low energies. Finally, with the help of this new tool, I will reinvestigate if dark matter can source the positron excess and I will set limits on MeV dark matter candidates
  • Thumbnail Image
    Item