Personne

Andrey Shkerin

Cette personne n’est plus à l’EPFL

Dilaton-assisted generation of the Fermi scale from the Planck scale

In scale-invariant theories of gravity the Planck mass M-p, which appears due to spontaneous symmetry breaking, can be the only scale at the classical level. It was argued that the second scale can be generated by a quantum nonperturbative gravitational ef ...

American Physical Society2019

Vibrational modes of Q-balls

Andrey Shkerin

We study linear perturbations of classically stable Q-balls in theories admitting analytic solutions. Although the corresponding boundary value problem is non-Hermitian, the analysis of perturbations can also be performed analytically in certain regimes. W ...

American Physical Society2018

On massive Nambu-Goldstone fields

Andrey Shkerin

We consider two theories undergoing the same spontaneous symmetry breaking pattern but with different representations of an order parameter under the Lorentz group. The effective description of the first theory includes a massive Nambu-Goldstone field, whi ...

EDP SCIENCES2018

Euclidean classical solutions in quantum field theory and gravity: Higgs vacuum metastability and the hierarchy problem

Andrey Shkerin

The thesis is dedicated to two groups of questions arising in modern particle physics and cosmology. The first group concerns with the problem of stability of the electroweak (EW) vacuum in different environments. Due to its phenomenological significance, ...

EPFL2018

Towards a non-perturbative approach to the Hierarchy problem

Andrey Shkerin

In this report, based on [1], we suggest that the hierarchy between the Electroweak (EW) and the Planck scales can emerge due to a nonperturbative effect that relates low-energy and strong-gravity physics. In this mechanism, the EW scale results from an ex ...

EDP SCIENCES2018

Conformal symmetry: Towards the link between the Fermi and the Planck scales

Mikhail Chapochnikov, Andrey Shkerin

If the mass of the Higgs boson is put to zero, the classical Lagrangian of the Standard Model (SM) becomes conformally invariant (CI). Taking into account quantum non-perturbative QCD effects violating CI leads to electroweak symmetry breaking with the sca ...

ELSEVIER SCIENCE BV2018

Gravity, scale invariance and the hierarchy problem

Mikhail Chapochnikov, Andrey Shkerin

Combining the quantum scale invariance with the absence of new degrees of freedom above the electroweak scale leads to stability of the latter against perturbative quantum corrections. Nevertheless, the hierarchy between the weak and the Planck scales rema ...

Springer Nature2018

Solving puzzles of spontaneously broken spacetime symmetries

Andrey Shkerin

We establish a classical analog of the Nambu-Goldstone theorem for spontaneous breaking of spacetime symmetries. It provides a counting rule for independent Nambu-Goldstone fields and states which of them are gapped. We demonstrate that only those symmetry ...

American Physical Society2018

Characteristic modes of vibration of Q-balls

Andrey Shkerin

In this report, based on [1], we study analytically small perturbations of classically stable Q-balls in 3+1 dimensions. Models with flat and polynomial potentials are considered. We find that large Q-balls in the model with the flat potential possess soft ...

EDP SCIENCES2018

Electroweak vacuum stability in the Higgs-Dilaton theory

Andrey Shkerin

We study the stability of the Electroweak (EW) vacuum in a scale-invariant extension of the Standard Model and General Relativity, known as a Higgs-Dilaton theory. The safety of the EW vacuum against possible transition towards another vacuum is a necessar ...

Springer Nature2017