A5057988369- Black Holes and Theoretical Physics
- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Noncommutative and Quantum Gravity Theories
- Galaxies: Formation, Evolution, Phenomena
- Quantum Chromodynamics and Particle Interactions
- Dark Matter and Cosmic Phenomena
- Geophysics and Gravity Measurements
- Computational Physics and Python Applications
- Pulsars and Gravitational Waves Research
- Quantum Electrodynamics and Casimir Effect
- Astrophysical Phenomena and Observations
- Earth Systems and Cosmic Evolution
- Relativity and Gravitational Theory
- Astrophysics and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Astronomy and Astrophysical Research
- Homotopy and Cohomology in Algebraic Topology
- Physics of Superconductivity and Magnetism
- Quantum, superfluid, helium dynamics
- Stellar, planetary, and galactic studies
- Algebraic structures and combinatorial models
- Stochastic processes and financial applications
- Astrophysics and Star Formation Studies
- Quantum many-body systems
Instituto de Física Teórica
2011-2025
Stanford University
2013-2022
SLAC National Accelerator Laboratory
1997-2017
Kavli Institute for Particle Astrophysics and Cosmology
2014-2017
Menlo School
2013-2017
University of Chicago
1958-2014
University of Pennsylvania
2014
University of California, Santa Barbara
1998-2012
Stanford Synchrotron Radiation Lightsource
1997-2004
Institute for Advanced Study
2000
We analyze the spectrum of density perturbations generated in models recently discovered ``D-cceleration'' mechanism inflation. In this scenario, strong coupling quantum field theoretic effects sum to provide a Dirac-Born-Infeld--like action for inflaton. show that model has strict lower bound on non-Gaussianity cosmic microwave background radiation power at an observable level, and is thus falsifiable. This, particular, observationally distinguishes from traditional slow-roll inflation by...
We present a simple mechanism for obtaining large-field inflation, and hence gravitational wave signature, from string theory compactified on twisted tori. For nil manifolds, we obtain leading inflationary potential proportional to ${\ensuremath{\phi}}^{2/3}$ in terms of the canonically normalized field $\ensuremath{\phi}$, yielding predictions tilt power spectrum tensor-to-scalar ratio, ${n}_{s}\ensuremath{\approx}0.98$ $r\ensuremath{\approx}0.04$ with 60 e-foldings inflation; note also...
Wrapped branes in string compactifications introduce a monodromy that extends the field range of individual closed-string axions to beyond Planck scale. Furthermore, approximate shift symmetries system naturally control corrections axion potential. This suggests general mechanism for chaotic inflation driven by monodromy-extended axions. We systematically analyze this possibility and show is compatible with moduli stabilization can be realized many types compactifications, including warped...
Causality on the gravity side of AdS/CFT correspondence restricts motion moduli space $\mathcal{N}=4$ super Yang-Mills theory by imposing a speed limit how fast scalar field may roll. This effect can be traced to higher-derivative operators arising from integrating out light degrees freedom near origin. In strong coupling theory, dynamics is well approximated Dirac-Born-Infeld Lagrangian for probe D3-brane moving toward horizon AdS Poincar\'e patch, combined with an estimate (ultimately...
We propose correspondences between 4d quantum field theories with N=2,1,0 (super)conformal invariance and Type IIB string theory on various orbifolds. argue using the spacetime theory, check beta functions (exactly for N=2,1 so far at 1-loop gauge couplings in N=0 case), that these have conformal fixed lines. The latter case potentially gives well-defined non-supersymmetric vacua of a mechanism making curvature cosmological constant small nontrivial coupling. suggest correspondence...
We initiate a holographic model building approach to `strange metallic' phenomenology. Our couples neutral Lifshitz-invariant quantum critical theory, dual bulk gravitational background, finite density of gapped probe charge carriers, dually described by D-branes. In the physical regime temperature much lower than and gap, we exhibit anomalous scalings frequency dependent conductivity. Choosing dynamical exponent z appropriately can match non-Fermi liquid scalings, such as linear...
We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes physics inflation. focus on prospects for using CMB to differentiate various inflationary mechanisms. In particular, a detection primordial B‐mode would demonstrate that inflation occurred at very high energy scale, and inflaton traversed super‐Planckian distance in field space. explain how such or constraint illuminate aspects Planck scale. Moreover, can constrain scale‐dependence...
A bstract The $$ T\overline{T} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>T</mml:mi> <mml:mover> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> deformation of a conformal field theory has dual description as cutoff AdS 3 spacetime, at least the level pure 3d gravity. We generalize this in such way that it builds up patch bulk dS spacetime instead. At each step along trajectory space 2 d theories, is deformed by specific combination and two-dimensional cosmological...
We present Poincare invariant domain wall (``3-brane'') solutions to some 5-dimensional effective theories which can arise naturally in string theory. In particular, we find where exist for arbitrary values of the brane tension, certain restricted forms bulk interactions. describe examples theory it would be natural quantum corrections tension (arising from fluctuations modes with support on brane) maintain required form action. such cases, persist presence these so that no 4d cosmological...
We propose descriptions of interacting (2,0) supersymmetric theories without gravity in six dimensions the infinite momentum frame. They are based on large $N$ limit quantum mechanics or 1+1 dimensional field moduli space instantons $\IR^4$.
We present a framework for de Sitter model building in type IIA string theory, illustrated with specific examples. find metastable (dS) minima of the potential moduli obtained from compactification on product two nil three-manifolds (which have negative scalar curvature) combined orientifolds, branes, fractional Chern-Simons forms, and fluxes. As discrete quantum number is taken large, curvature, field strengths, inverse volume, four-dimensional coupling become parametrically small, Hubble...
We show how backreaction of the inflaton potential energy on heavy scalar fields can flatten inflationary potential, as adjust to their most energetically favorable configuration. This mechanism operates in previous UV-complete examples axion monodromy inflation---flattening a would-be quadratic one linear field---but occurs more generally, and we illustrate effect with several examples. Special choices compactification minimizing may realize chaotic inflation but argue that flatter such...
Flux couplings to string theory axions yield super-Planckian field ranges along which the axion potential energy grows. At same time, other aspects of physics remain essentially unchanged these large displacements, respecting a discrete shift symmetry with sub-Planckian period. After general overview this monodromy effect and its application large-field inflation, we present new classes specific models monomial potentials $\mu^{4-p}\phi^p$. A key simplification in is that inflaton plays...
A bstract We propose a new example of entanglement knitting spacetime together, satisfying series checks the corresponding von Neumann and Renyi entropies. The conjectured dual de Sitter in d + 1 dimensions involves two coupled CFT sectors constrained by residual -dimensional gravity. In = 2 case, gravitational constraints spectrum are relatively tractable. identify finite portion each Hilbert space relevant for Sitter. Its maximum energy level coincides with transition to universal Cardy...
A bstract We obtain microstates accounting for the Gibbons-Hawking entropy in dS 3 , along with a subleading logarithmic correction, from solvable T $$ \overline{T} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mi>T</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> + Λ 2 deformation of seed CFT sparse light spectrum. The arise as dressed states near dimension ∆ = c/ 6, associated Hawking-Page transition; they dominate real spectrum deformed theory. exhibit an...
We provide a method for obtaining simple models of supersymmetry breaking, with all small mass scales generated dynamically, and illustrate it explicit examples. start from perturbative such as O'Raifeartaigh Fayet models, that would respect an $R$ symmetry if their input parameters transformed the superpotential does. By coupling system to pure supersymmetric Yang-Mills theory (or more general gauge dynamically vacuum expectation values), these are replaced by powers its dynamical scale in...