A5015413926- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Black Holes and Theoretical Physics
- Noncommutative and Quantum Gravity Theories
- Astrophysics and Cosmic Phenomena
- Quantum Electrodynamics and Casimir Effect
- Galaxies: Formation, Evolution, Phenomena
- Atomic and Subatomic Physics Research
- Experimental and Theoretical Physics Studies
- Gamma-ray bursts and supernovae
- semigroups and automata theory
- Particle Accelerators and Free-Electron Lasers
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Cold Atom Physics and Bose-Einstein Condensates
- Pulsars and Gravitational Waves Research
Loyola University Chicago
2018-2024
Cornell University
2020
Universidad de Antioquia
2015-2019
Tel Aviv University
2015-2018
The University of Texas at Austin
2011-2015
Rutgers, The State University of New Jersey
2014
University of California, Santa Cruz
2014
Texas Neurology
2012
keV-scale gauge-singlet fermions, when allowed to mix with the active neutrinos, are elegant dark matter (DM) candidates. They produced in early Universe via Dodelson-Widrow mechanism and can be detected as they decay very slowly, emitting x-rays. In absence of new physics, this hypothesis is virtually ruled out by astrophysical observations. Here, we show that interactions among neutrinos allow these sterile make up all DM while safely evading current experimental bounds. The existence...
Using the AdS/CFT correspondence, we construct holographic dual of a tunneling instanton describing Schwinger pair creation in de Sitter space. Our approach allows us to extract critical value electric field for which potential barrier disappears, rendering vacuum unstable. In addition, compute large-$\ensuremath{\lambda}$, large-${N}_{c}$ corrections nucleation rate and find that it agrees with previous expectations based on perturbative computations. As by-product this investigation, study...
The cosmological relaxation of the electroweak scale has been proposed as a mechanism to address hierarchy problem Standard Model. A field, relaxion, rolls down its potential and, in doing so, scans squared mass parameter Higgs, relaxing it parametrically small value. In this work, we promote relaxion an inflaton. We couple Abelian gauge bosons, thereby introducing necessary dissipation which slows field last stages. describe novel reheating mechanism, relies on gauge-boson production...
Secret neutrino interactions can play an essential role in the origin of dark matter. We present anatomy production mechanisms for sterile matter, a keV-scale gauge-singlet fermion that mixes with active neutrinos, presence new vector boson mediating secret among neutrinos. identify three regimes boson's mass and coupling where it makes distinct impact on matter through dispersion relations and/or scattering rates. also analyze models gauged...
When the singlet-doublet fermion dark matter model is extended with additional $Z_2$--odd real singlet scalars, neutrino masses and mixings can be generated at one-loop level. In this work, we discuss salient features arising from combination of two resulting simplified models. $Z_2$-lightest odd particle a scalar singlet, $\operatorname{Br}(\mu\to e \gamma)$ could measurable provided that mixing small enough. scenario, also new decay channels vector-like fermions into scalars generate...
In this short note we use holographic methods to study the response of quantum critical points with hyperscaling violation a disturbance caused by massive charged particle. We give analytical expressions for two-point functions fluctuations probe as function arbitrary (allowed) values exponent {\theta} and dynamical z. point out existence markedly different behaviors in parameter space z at late times. particular, expected, late-time dynamics becomes independent its inertial mass range...
A bstract Using the Hubeny-Rangamani-Takayanagi (HRT) conjectured formula for entanglement entropy in context of AdS/CFT correspondence with time-dependent backgrounds, we investigate relation between bulk null energy condition (NEC) stress-energy tensor strong sub-additivity (SSA) property boundary theory. In a background that interpolates an AdS to AdS-Reissner-Nordstrom-type geometry, find generically there always exists critical surface beyond which violation NEC would naively occur....
In this paper we study some thermal properties of quantum field theories in de Sitter space by means holographic techniques. We focus on the static patch and assume that fields are standard Bunch-Davies vacuum. More specifically, follow stochastic motion a massive charged particle due to its interaction with Hawking radiation. The process is described terms theory Brownian inhomogeneous media associated Langevin dynamics. At late times, find undergoes regime slow diffusion never reaches...
A bstract The Standard Model predicts a long-range force, proportional to $$ {G}_F^2/{r}^5 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>G</mml:mi> <mml:mi>F</mml:mi> <mml:mn>2</mml:mn> </mml:msubsup> <mml:mo>/</mml:mo> <mml:msup> <mml:mi>r</mml:mi> <mml:mn>5</mml:mn> </mml:msup> </mml:math> , between fermions due the exchange of pair neutrinos. This quantum force is feeble and has not been observed yet. In this paper, we compute in presence neutrino...
In order to generate, in the context of gauge mediation, a Higgs mass around 126 GeV that avoids little hierarchy problem, we explore set models where messengers are directly coupled new vector-like fields at TeV scale addition usual low energy degrees freedom. We find this context, stop masses lighter than 2 and large A-terms generated, thereby improving issues fine tuning.
We extend the use of holography to investigate scrambling properties various physical systems. Specifically, we consider: (i) non-conformal backgrounds black $Dp$ branes, (ii) asymptotically Lifshitz holes, and (iii) $AdS$ solutions Gauss-Bonnet gravity. disruption entanglement entropy as a probe chaotic features such Our analysis shows that these theories share same type behavior conformal they undergo chaos; however, in case gravity, find stark difference evolution mutual information for...
We examine an extension of the Standard Model that addresses dark matter puzzle and generates Dirac neutrino masses through radiative seesaw mechanism. The new field content includes a scalar plays important role in setting relic abundance matter. analyze phenomenology light direct, indirect, collider searches In this framework, candidate is particle mixture singlet-doublet fields with mass ${m}_{{\ensuremath{\chi}}_{1}^{0}}\ensuremath{\lesssim}1.1\text{ }\text{ }\mathrm{TeV}$. find allowed...
The exchange of two neutrinos at one loop leads to a long-range parity-violating force between fermions. We explore the two-neutrino in backdrop atomic physics. point out that this is largest Standard Model and calculate effect experiments probe parity violation by measuring optical rotation light as it passes through sample vaporized atoms. perform explicit calculations for hydrogen atom demonstrate effect. Although we find too small be observed foreseeable future, our approach may applied...
We present a model of partially interacting dark matter within the framework supersymmetry with gauge mediated symmetry breaking. Dark sector atoms are produced through Affleck-Dine baryogenesis in while avoiding production $Q$-ball relics. discuss astrophysical constraints relevant for this and possibility galactic disk formation. In addition, jet emission from rotating black holes is discussed context class models.
A bstract The neutrino force results from the exchange of a pair neutrinos. background can significantly influence this force. In work, we present comprehensive calculation in various backgrounds with spin dependence taken into account. particular, calculate spin-independent and spin-dependent parity-conserving forces, addition to parity-violating forces without presence for both isotropic anisotropic backgrounds. Compared vacuum case, effectively violate Lorentz invariance lead additional...
We examine the possibility that accretion of Dissipative Dark Matter (DDM) onto Active Galactic Nuclei (AGN) contributes to growth rate Super Massive Black Holes (SMBHs). Such a scenario could alleviate tension associated with anomalously large SMBHs measured at very early cosmic times, as well observations indicate most massive occurs before $z\sim6$, little later times. These are not readily explained within standard AGN theory. find range in parameter space DDM models where we both expect...
Abstract Novel neutrino self-interaction can open up viable parameter space for the relic abundance of sterile-neutrino dark matter (S ν DM). In this work, we constrain target using core-collapse supernova which features same fundamental process and a similar environment to early universe era when S DM is dominantly produced. We present detailed calculation effects massive scalar mediated on cooling rate, including derivation thermal potential in presence non-zero chemical potentials from...
We discuss the implications for gamma ray burst studies of a dark unbroken $U(1{)}_{D}$ sector that couples predominantly through gravity to visible sector. The dominant matter component remains neutral under $U(1{)}_{D}$. collapsar model is assumed explain origin long bursts. main idea that, by measuring change in stellar black hole spin during duration burst, one can make inferences about existence accretion disk. This could potentially provide evidence
We present an effective model where the inflaton is a relaxion that scans Higgs mass and sets it at weak scale. The dynamics consist of long epoch in which inflation due to shallow slope potential, followed by few number e-folds slow-roll maintained thanks dissipation via non-perturbative gauge-boson production. same gauge bosons give rise strong electric field triggers production electron-positron pairs Schwinger mechanism. subsequent thermalization these particles provides novel mechanism...
The neutrino force results from the exchange of a pair neutrinos. A background can significantly influence this force. In work, we present comprehensive calculation in various backgrounds with spin dependence taken into account. particular, calculate spin-independent and spin-dependent parity-conserving forces, addition to parity-violating forces without presence for both isotropic anisotropic backgrounds. Compared vacuum case, effectively violate Lorentz invariance lead additional terms...