A5048699381- Black Holes and Theoretical Physics
- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Noncommutative and Quantum Gravity Theories
- Galaxies: Formation, Evolution, Phenomena
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Relativity and Gravitational Theory
- Quantum Chromodynamics and Particle Interactions
- Geophysics and Gravity Measurements
- Nonlinear Waves and Solitons
- Computational Physics and Python Applications
- Dark Matter and Cosmic Phenomena
- Advanced Differential Geometry Research
- Solar and Space Plasma Dynamics
- Advanced Mathematical Physics Problems
- Advanced Mathematical Theories and Applications
- Earth Systems and Cosmic Evolution
- International Science and Diplomacy
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Quantum Electrodynamics and Casimir Effect
- Quantum Mechanics and Applications
- Advanced Topics in Algebra
- Algebraic structures and combinatorial models
Stanford University
2015-2024
Memorial
2022
Kavli Institute for Theoretical Sciences
2022
Varian Medical Systems (United States)
2016
University of Chicago
2014
SLAC National Accelerator Laboratory
1998-2011
Kyoto University
2005-2009
Yukawa Institute for Theoretical Physics
2008
Ludwig-Maximilians-Universität München
2008
European Organization for Nuclear Research
1985-2000
We outline the construction of metastable de Sitter vacua type IIB string theory. Our starting point is highly warped compactifications with nontrivial NS and RR three-form fluxes. By incorporating known corrections to superpotential from Euclidean D-brane instantons or gaugino condensation, one can make models all moduli fixed, yielding a supersymmetric AdS vacuum. Inclusion small number $\overline{\mathrm{D}3}$-branes in resulting geometry allows uplift minimum it ground state. The...
We investigate the embedding of brane inflation into stable compactifications string theory. At first sight a warped compactification geometry seems to produce naturally flat inflaton potential, evading one well-known difficulty brane-antibrane scenarios. Careful consideration closed moduli reveals further obstacle: superpotential stabilization volume typically modifies potential and renders it too steep for inflation. discuss non-generic conditions under which this problem does not arise....
It is shown that extremal magnetic black hole solutions of N = 2 supergravity coupled to vector multiplets $X^\Lambda$ with a generic holomorphic prepotential $F(X^\Lambda)$ can be described as supersymmetric solitons which interpolate between maximally symmetric limiting at spatial infinity and the horizon. A simple exact solution found for special case ratios are real, it seen logarithm conformal factor metric equals Kahler potential on multiplet moduli space. Several examples discussed in detail.
We find a general principle which allows one to compute the area of horizon $N=2$ extremal black holes as an extremum central charge. One considers ADM mass equal charge function electric and magnetic charges moduli extremizes this in space (a minimum corresponds fixed point attraction). The value square provides horizon, depends only on charges. doubling unbroken supersymmetry at attraction for near is derived via conformal flatness Bertotti-Robinson-type geometry. These results provide...
There exists a widely held notion that gravitational effects can strongly violate global symmetries. If this is correct, it may lead to many important consequences. We argue, in particular, nonperturbative the axion theory strong violation of CP invariance unless they are suppressed by an extremely small factor g\ensuremath{\lesssim}${10}^{\mathrm{\ensuremath{-}}82}$. One could hope problem disappears if one represents symmetry pseudoscalar field as gauge Ogievetsky-Polubarinov-Kalb-Ramond...
The macroscopic entropy-area formula for supersymmetric black holes in $N=2, 4, 8$ theories is found to be universal: $d=4$ it always given by the square of largest central charges extremized moduli space. proof universality based on fact that doubling unbroken supersymmetry near hole horizon requires all other than $Z=M$ vanish at attractor point $N=4, 8$. ADM mass extremum can computed terms duality symmetric quartic invariants which are independent. extension these results $d=5$, $N=1, 2,...
We present a superconformal master action for class of supergravity models with one arbitrary function defining the Jordan frame. It leads to gauge-invariant real vector multiplet, which upon gauge fixing describes massive or dual formulation linear multiplet and tensor field. In both cases have scalar, inflaton, naturally suited single-field inflation. Vectors tensors required by supersymmetry complement single scalar do not acquire vacuum expectation values during inflation, so there is no...
We develop a new class of chaotic inflation models with spontaneously broken conformal invariance. Observational consequences broad such are stable respect to strong deformations the scalar potential. This universality is critical phenomenon near point enhanced symmetry, SO(1,1), in case inflation. It appears because exponential stretching moduli space and resulting flattening potentials upon switching from Jordan frame Einstein this models. result resembles inhomogeneities during...
Recently, several broad classes of inflationary models have been discovered whose cosmological predictions, in excellent agreement with Planck, are stable respect to significant modifications the inflaton potential. Some based on a nonminimal coupling gravity. These models, which we call ξ attractors, describe universal attractors (including Higgs inflation) and induced inflation models. Another class describes conformal Starobinsky T models) their generalization α attractors. The aim this...
We introduce a novel non-minimal coupling between gravity and the inflaton sector. Remarkably, for large values of this all models asymptote to universal attractor. This behavior is independent original scalar potential generalizes attractor in phi^4 theory with gravity. The located `sweet spot' Planck's recent results.
We identify a particularly simple class of supergravity models describing superconformal coupling matter to supergravity. In these models, which we call the canonical (CSS) kinetic terms in Jordan frame are canonical, and scalar potential is same as global theory. The pure part total action has local Poincare supersymmetry, whereas chiral vector multiplets coupled have larger symmetry. scale-free globally supersymmetric theories, such NMSSM with scale-invariant superpotential, can be...
We find a way to represent the Starobinsky model in terms of simple conformally invariant theory with spontaneous symmetry breaking. also present superconformal theory, which, upon breaking symmetry, provides consistent supergravity generalization model.
We describe a way to construct supergravity models with an arbitrary inflaton potential $V(\ensuremath{\phi})$ and show that all other scalar fields in this class of can be stabilized at the inflationary trajectory by proper choice K\"ahler potential.
We consider a broad class of inflationary models that arise naturally in supergravity. They are defined terms parameter $\alpha$ determines the curvature and cutoff these models. As function this parameter, we exhibit predictions generically interpolate between two attractor points. At small $\alpha$, resulting model is plateau-type with $n_s = 1 - 2 / N$ $r 12 \alpha N^2$. For $\alpha 1$, coincide Starobinsky Higgs inflation. In contrast, for large theory asymptotes to quadratic inflation,...
We discuss N=1 supergravity inflationary models based on two chiral multiplets, the inflaton and goldstino superfield. Using superconformal methods for these models, we propose to replace unconstrained multiplet by nilpotent one associated with non-linearly realized supersymmetry of Volkov-Akulov type. In new cosmological sgoldstino is proportional a bilinear combination fermionic goldstinos. It does not acquire any vev, nor require stabilization, affect evolution. explain universal relation...
We review the advanced version of KKLT construction and pure $d=4$ de Sitter supergravity, involving a nilpotent multiplet, with regard to various conjectures that state cannot exist in string theory. explain why we consider these problematic not well motivated, recently proposed alternative theory models dark energy, ignoring vacuum stabilization, are ruled out by cosmological observations at least $3\sigma$ level, i.e. more than $99.7\%$ confidence.
Abstract We investigate the two-stage inflation regime in theory of hybrid cosmological α -attractors. The spectrum inflationary perturbations is compatible with latest Planck/BICEP/Keck Array results, thanks to attractor properties model. However, at smaller scales, it may have a very high peak controllable width and position, leading copious production primordial black holes (PBH) generation stochastic background gravitational waves (SGWB).
In supersymmetric theories the mass of any state is bounded below by values some its charges. The corresponding bounds in case Schwarzschild ($M\ensuremath{\ge}0$) and Reissner-Nordstr\"om ($M\ensuremath{\ge}|q|$) black holes are known to coincide with requirement that naked singularities be absent. Here we investigate ${[U(1)]}^{2}$ charged dilaton this context. extreme solutions shown saturate supersymmetry bound $N=4$, $d=4$ supergravity, or dimensionally reduced superstring theory....
We discuss a generalized form of IIA/IIB supergravity depending onall R-R potentials C(p) (p = 0,1,...,9) as the effective field theory type superstring theory. For IIA case we explicitly break this democracy to either p⩽3 or p⩾5, which allows us write new bulk action that can be coupled N 1 supersymmetric brane actions.
We show that under variation of moduli fields $\ensuremath{\varphi}$ the first law black hole thermodynamics becomes $dM\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\frac{\ensuremath{\kappa}\mathrm{dA}}{8\ensuremath{\pi}}+\ensuremath{\Omega}dJ+\ensuremath{\psi}dq+\ensuremath{\chi}dp\ensuremath{-}\ensuremath{\Sigma}d\ensuremath{\varphi}$, where $\ensuremath{\Sigma}$ are scalar charges. Also Arnowitt-Desner-Misner mass is extremized at fixed $A$, $J$, $(p,q)$ when take value...