Publications de Sergey Sibiryakov

Linearized supergravity with a dynamical preferred frame

We study supersymmetric extension of the Einstein-aether gravitational model where local Lorentz invariance is broken down to the subgroup of spatial rotations by a vacuum expectation value of a timelike vector field called aether. Embedding aether into a ...

Springer Nature2021

BBN constraints on universally-coupled ultralight scalar dark matter

Sergey Sibiryakov

Ultralight scalar dark matter can interact with all massive Standard Model particles through a universal coupling. Such a coupling modifies the Standard Model particle masses and affects the dynamics of Big Bang Nucleosynthesis. We model the cosmological e ...

Springer Nature2020

Secular effects of ultralight dark matter on binary pulsars

Sergey Sibiryakov, Diego Blas Temino

Dark matter (DM) can consist of very light bosons behaving as a classical scalar field that experiences coherent oscillations. The presence of this DM field would perturb the dynamics of celestial bodies, either because the (oscillating) DM stress tensor m ...

American Physical Society2020

Semiclassical S-matrix and black hole entropy in dilaton gravity

Sergey Sibiryakov

We use complex semiclassical method to compute scattering amplitudes of a point particle in dilaton gravity with a boundary. This model has nonzero minimal black hole mass M-cr. We find that at energies below M-cr the particle trivially scatters off the bo ...

Springer Nature2020

Non-perturbative probability distribution function for cosmological counts in cells

Sergey Sibiryakov, Mikhail Ivanov

We present a non-perturbative calculation of the 1-point probability distribution function (PDF) for the spherically-averaged matter density field. The PDF is represented as a path integral and is evaluated using the saddle-point method. It factorizes into ...

IOP PUBLISHING LTD2019

Towards the renormalization group flow of Horava gravity in 3+1 dimensions

Sergey Sibiryakov, Mario Herrero Valea

We compute the renormalization group running of the Newton constant and the parameter lambda in (3 + 1)-dimensional projectable Horava gravity. We use the background-field method, expanding around configurations with flat spatial metric, but nonvanishing s ...

American Physical Society2019

Inflationary perturbations with Lifshitz scaling

Sergey Sibiryakov

Instead of Lorentz invariance, gravitational degrees of freedom may obey Lifshitz scaling at high energies, as it happens in Horava's proposal for quantum gravity. We study consequences of this proposal for the spectra of primordial perturbations generated ...

IOP PUBLISHING LTD2019

Supergravity with broken Lorentz invariance: theory and phenomenological consequences

Sergey Sibiryakov

We construct and study supersymmetric extension of the Einstein-aether gravitational theory. Using superfield formalism we carry out unique linearized Lorentz violating supergravity action invariant under super-gauge transformations and obtain its bosonic ...

IOP PUBLISHING LTD2019

Infrared resummation for biased tracers in redshift space

Sergey Sibiryakov, Mikhail Ivanov

2018

Renormalization of gauge theories in the background-field approach

Sergey Sibiryakov, Diego Blas Temino, Mario Herrero Valea

Springer Nature2018

Femtolensing by dark matter revisited

Wei Xue, Sergey Sibiryakov

Femtolensing of gamma ray bursts (GRBs) has been put forward as an exciting possibility to probe exotic astrophysical objects with masses below 10(-13) solar masses such as small primordial black holes or ultra-compact dark matter minihalos, made up for in ...

IOP PUBLISHING LTD2018

Galactic rotation curves versus ultralight dark matter: Implications of the soliton-host halo relation

Sergey Sibiryakov, Diego Blas Temino

Bosonic ultralight dark matter (ULDM) would form cored density distributions at the center of galaxies. These cores, seen in numerical simulations, admit analytic description as the lowest energy bound state solution ("soliton") of the Schroedinger-Poisson ...

American Physical Society2018

Horava Gravity is Asymptotically Free in 2+1 Dimensions

Sergey Sibiryakov, Diego Blas Temino, Mario Herrero Valea

We compute the beta functions of marginal couplings in projectable Horava gravity in 2 + 1 spacetime dimensions. We show that the renormalization group flow has an asymptotically free fixed point in the ultraviolet (UV), establishing the theory as a UV-com ...

American Physical Society2017

Testing Lorentz invariance of dark matter with satellite galaxies

Sergey Sibiryakov, Diego Blas Temino

We develop the framework for testing Lorentz invariance in the dark matter sector using galactic dynamics. We consider a Lorentz violating (LV) vector field acting on the dark matter component of a satellite galaxy orbiting in a host halo. We introduce a n ...

Iop Publishing Ltd2017

Ultralight Dark Matter Resonates with Binary Pulsars

Sergey Sibiryakov, Diego Blas Temino

We consider the scenario where dark matter (DM) is represented by an ultralight classical scalar field performing coherent periodic oscillations. We point out that such DM perturbs the dynamics of binary systems either through its gravitational field or vi ...

American Physical Society2017

Constraints on violation of Lorentz invariance from atmospheric showers initiated by multi-TeV photons

Sergey Sibiryakov

Parameterizing hypothetical violation of Lorentz invariance at high energies using the framework of effective quantum field theory, we discuss its effect on the formation of atmospheric showers by very-high-energy gamma rays. In the scenario where Lorentz ...

Iop Publishing Ltd2017

Time-sliced perturbation theory for large scale structure I: general formalism

Sergey Sibiryakov, Diego Blas Temino, Mikhail Ivanov

We present a new analytic approach to describe large scale structure formation in the mildly non-linear regime. The central object of the method is the time-dependent probability distribution function generating correlators of the cosmological observables ...

Iop Publishing Ltd2016

On constraining the speed of gravitational waves following GW150914

Sergey Sibiryakov, Diego Blas Temino, Mikhail Ivanov

We point out that the observed time delay between the detection of the signal at the Hanford and Livingston LIGO sites from the gravitational wave event GW150914 places an upper bound on the speed of propagation of gravitational waves, c (gw) ae(2) 1.7 in ...

Springer Verlag2016

Renormalization of Horava gravity

Sergey Sibiryakov, Diego Blas Temino, Mario Herrero Valea

We prove perturbative renormalizability of projectable Horava gravity. The key element of the argument is the choice of a gauge which ensures the correct anisotropic scaling of the propagators and their uniform falloff at large frequencies and momenta. Thi ...

American Physical Society2016

Emergent Lorentz invariance with chiral fermions

Sergey Sibiryakov

We study the renormalization group flow in strongly interacting field theories in the fermion sector corresponding to the transition from theories without a Lorentz invariance at high energies to theories with an approximate Lorentz invariance in the infra ...

Springer Verlag2016