30 citations · 85 across the 10 of their papers we have counts for
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Unperturbation theory: reconstructing Lagrangians from instanton fluctuations
Farahmand Hasanov, Nikita Kolganov
Instantons present a deep insight into non-perturbative effects both in physics and mathematics. While leading instanton effects can be calculated simply as an exponent of the inst…
Nonequilibrium Schwinger-Keldysh formalism for density matrix states: analytic properties and implications in cosmology
Andrei O. Barvinsky, Nikita Kolganov
Motivated by cosmological Hartle-Hawking and microcanonical density matrix prescriptions for the quantum state of the Universe we develop Schwinger-Keldysh in-in formalism for gene…
Real-time diagram technique for instantonic systems
Nikita Kolganov
The Schwinger-Keldysh diagram technique is usually involved in the calculation of real-time in-in correlation functions. In the case of a thermal state, one can analytically contin…
Classical and quantum butterfly effect in nonlinear vector mechanics
Nikita Kolganov, Dmitrii A. Trunin
We establish the correspondence between the classical and quantum butterfly effects in nonlinear vector mechanics with the broken symmetry. On one hand, we analytically calc…
Large topological quantum computer
Nikita Kolganov, Sergey Mironov, Andrey Morozov
Chern-Simons topological quantum computer is a device that can be effectively described by the Chern-Simons topological quantum field theory and used for quantum computations. Quan…
Quantum -matrices as universal qubit gates
Nikita Kolganov, Andrey Morozov
We study the Chern-Simons approach to the topological quantum computing. We use quantum -matrices as universal quantum gates and study the approximations of some one-q…
Dynamics of the generalized unimodular gravity theory
A. O. Barvinsky, N. Kolganov, A. Kurov +1
The Hamiltonian formalism of the generalized unimodular gravity theory, which was recently suggested as a model of dark energy, is shown to be a complicated example of constrained…