Archive 2013

Rank-frequency relation for Chinese characters

Armen Allahverdyan

Yerevan Physics Institute

14:00, Saturday, 21 December 2013

(YSU, Physics Faculty, room 326)

Abstract: We show that the Zipf's law for Chinese characters perfectly holds for sufficiently short texts. The scenario of its validity is similar to the Zipf's law for words in short English texts. We focus on short texts, since for the sake of the rank-frequency analysis, long texts are just mixtures of shorter, thematically homogenous pieces. For long texts (or for mixtures of short texts), the Zipf's law holds for a relatively small range of ranks. From comparative analysis of the rank-frequency relations for Chinese and English, we suggest that the characters play for Chinese writers the same role as the words for those writing within alphabetical systems.

How to define fluctuations of work in the quantum situation

Armen Allahverdyan

14:00, Saturday, 14 December 2013

(YSU, Physics Faculty, room 326)

Abstract:The first and second laws of statistical thermodynamics are formulated via the concept of work, i.e. the (average) energy exchanged by a quantum system driven via a time-dependent Hamiltonian. To develop a fuller understanding of work and its quantum features, we need to represent it as an average of a fluctuating quantity. Straightforward attempts to solve this problem are well-known in literature, but they are physically unacceptable due to non-commutativity of the time-dependent Hamiltonian at different times. I propose a solution of this problem that is free of previous drawbacks. It allows to deduce a generalized (out of equilibrium) fluctuation theorem which relates the work to its equilibrium limit.

Meeting of members of ICTP Network and Volskswagen Regional Traning Network:Regional cooperation in 2014

14:00, Saturday, 7 December 2013

(YSU, Physics Faculty, room 326)

Armen Nersessian: I suggest to discuss our future actions within these regional (Armenia, Georgia,Iran, Turkey, Morocco, Ukraine, JINR-Dubna) projects, including proposals for scientific collaborations, exchange visits, organization of schools and workshops, as well as delivering of lecture courses for PhD students etc.

A CFT view of 3d black holes

Farhang Loran

Isfahan University of Technology, Isfahan

14:00, Saturday, 16 November 2013

(YSU, Physics Faculty, room 326)

Abstract: In this talk, we consider the causal structure and the thermodynamics of the three dimensional BTZ black holes. These black holes can be realized as (micro-) canonical ensembles in a two dimensional conformal field theory (CFT) located at the conformal boundary of the background geometry. We review the holographic renormalization method, which identifies the CFT central charge with the holomorphic Weyl anomaly.

State Exchange time in parabolic helium atom

Hayk Sarkisyan

Russian-Armenian University

14:00, Saturday, 9 November 2013

(YSU, Physics Faculty, room 326)

Quasienergies and dynamics of superconducting qubit in a finite-modulated field. II

Gor Abovyan

Yerevan State University

14:00, Saturday, 2 November 2013

(YSU, Physics Faculty, room 326)

Quasienergies and dynamics of superconducting qubit in a finite-modulated field

Gor Abovyan

Yerevan State University

14:00, Saturday, 26 October 2013

(YSU, Physics Faculty, room 326)

B-ghost in the pure spinor formalism for superstrings in nontrivial background

Ilya Bakhmatov

Institute of Theoretical Physics, State University of Sao Paulo

14:00, Saturday, 21 September 2013

(YSU, Physics Faculty, room 326)

Abstract: Description of superstrings using pure spinor formalism has the advantage of admitting covariant quantization, at the same time being manifestly spacetime supersymmetric. Construction of the Faddeev-Popov b-ghost in the pure spinor formalism will be reviewed, including the case of background electromagnetic field. This is a step towards the case of general background, which would allow covariant computation of multiloop string scattering amplitudes in curved backgrounds.

Adaptive machine and its thermodynamic cost

Armen Allahverdyan

Yerevan Physics Institute

14:00, Saturday, 7 September 2013

(YSU, Physics Faculty, room 326)

I report on the minimal thermodynamically consistent model for an adaptive machine that transfers particles from a higher chemical potential reservoir to a lower one. This model describes essentials of the inhomogeneous catalysis. It is supposed to function with the maximal current under uncertain chemical potentials: if they change, the machine tunes its own structure fitting it to the maximal current under new conditions.

This adaptation is possible under two limitations. (1) The machine's structure has to have a stored energy. (2) The machine has to malfunction at a constant environment due to structural fluctuations. We argue that several features of the adaptive machine are similar to those of living organisms (fitting to the environment, energy storage, aging).

Rational Calogero Model and Dunkl operators

David Karakhanyan

Yerevan Physics Institute

14:00, Friday, 21 June, 2013

(YSU, Physics Faculty, room 326)

Review of Computational Problems in Paid Search Advertising

Rouben Amirbekian

“Microsoft” Online Services Division (“Bing”)

14:00, Friday, 14 June, 2013

(YSU, Physics Faculty, room 326)

From Classical Bargmann-Michel-Telegdi electron to Dirac Equation

Alexei Deriglazov

Universidade Federal de Juiz de Fora

14:00, Saturday, 8 June, 2013

(YSU, Physics Faculty, room 326)

Skyrmions to Hopfions; Chern-Pontryagin to Chern-Simons

Tigran Tchrakyan

Dublin Institute for Advanced Study

14:00, Saturday, 1 June, 2013

(YSU, Physics Faculty, room 326)

Carnot cycle and attainability of maximal efficiency

Armen Allahverdyan

Yerevan Physics Institute

14:00, Saturday, 25 May, 2013

(YSU, Physics Faculty, room 326)

Universality in Chern-Simons theories and Lie Algebras. II

Ruben Mkrtchyan

Yerevan Physics Institute

14:00, Saturday, 4 May, 2013

(YSU, Physics Faculty, room 326)

Universality in Chern-Simons theories and Lie Algebras

Ruben Mkrtchyan

Yerevan Physics Institute

14:00, Saturday, 27 April, 2013

(YSU, Physics Faculty, room 326)

Two Dimensional Renormalization Group Flows in Next to Leading Order

Rubik Poghossian

Yerevan Physics Institute

14:00, Saturday, 20 April, 2013

(YSU, Physics Faculty, room 326)

Explicit Harmonic Analysis in Bianchi I-VII groups.II

Zhirayr Avetisyan

Yerevan State University

14:00, Saturday, 6 April, 2013

(YSU, Physics Faculty, room 326)

Explicit Harmonic Analysis in Bianchi I-VII groups

Zhirayr Avetisyan

Yerevan State University

14:00, Saturday, 30 March, 2013

(YSU, Physics Faculty, room 326)

Far-Infrared Optics of Thompson Helium Atom

Hayk Sarkisyan

Russian-Armenian University

14:00, Saturday, 23 March, 2013

(YSU, Physics Faculty, room 326)

Couplings in string theory and the B-field

Ruben Minasian

Institut de Physique Th´eorique, CEA/Saclay

14:00, Saturday, 9 March, 2013

(YSU, Physics Faculty, room 326)

Fermionic T-duality in type II supergravity

Ilya Bakhmatov

14:00, Saturday, 23 February, 2013

(YSU, Physics Faculty, room 326)

Duality between axially and vectorially gauge models. Part II

Gor Sarkissian

14:00, Saturday, 9 February, 2013

(YSU, Physics Faculty, room 333)

Duality between axially and vectorially gauge models

Gor Sarkissian

14:00, Saturday, 2 February, 2013

(YSU, Physics Faculty, room 333)

On the Zipf's Law

Armen Allahverdyan

14:00, Friday, 25 January, 2013

(YSU, Physics Faculty, room 333)

Exact results in turbulence and multifractal models

David Sahakian

14:00, Saturday, 19 January, 2013

(YSU, Physics Faculty, room 333)

Linear Quantum Fields in Cosmological Models

Zhirair Avetisyan (MPI, Leipzig)

14:30, Friday, 11 January, 2013

(YSU, Physics Faculty, room 333)