Jaroslav Ilnytskyi: Scientific Activity
Research Background
Published Papers
Participation in the conferences and symposia
Degrees and grants awarded
My scientific activity started in 1985 when I became a post
graduate student at the Institute for Theoretical Physics of
Ukrainian Academy of Sciences (supervisors Prof. I.R. Yukhnovskii
and Dr. M.P. Kozlovskii). My primary investigations were phase
transitions in the Ising and n-component model using the
collective variables (CV) method. This method was developed for
spin systems by I.R.Yukhnovskii and collaborators. It combines
the collective variables approach (developed previously for fluid
systems) with the renormalization group (RG) ideas. One of the
primary features of the CV method is that it is non-perturbative.
The self-consistent way of performing the RG transformation in
the CV method was developed (together with I.R. Yukhnovskii and
M.P. Kozlovskii). This helps to avoid the problems with the
choice of the RG parameter and with its influence on the final
results.
Other studies in the scope of these problems were connected with performing
perturbation theory within the CV method. This work continued the
earlier works of I.R. Yukhnovskii, I.O. Vakarchuk, Y.K. Rudavskii
and Y.V. Holovatch. The epsilon-expansion procedure, which
has originated from the Wilson RG approach, has been used in the CV method.
This allowed us to obtain stable and accurate results for the
critical indices in second order in epsilon (together with
M.P. Kozlovskii). The accurate comparison of the CV RG scheme
with the Wilson RG approach is also performed. This was done by
comparing different classes of diagrams in both cases. These
results were included in my Ph.D. thesis "Collective
Variables Method and the epsilon-expansion"
(1994, supervisors Prof. I.R.Yukhnovskii and Prof. M.P.Kozlovskii).
Further investigations started in 1995 involve computer simulations of
the phase transitions in the liquid crystalline materials. The lattice model of rotators
interacting via the angular part of the Berne-Pechukas intermolecular potential
has been proposed. As compared to widely exploited Lebwohl-Lasher model
this model contains a parameter of molecular elongation a which is used to
control the anisotropy of the potential. This model was studied by means of
Monte Carlo simulations near its orientational phase transition mimicking the
nematic-isotropic (NI) transition in liquid crystals. We obtain progressive
strengthening of the order of this transition as molecular elongation increases.
Reasonably good agreement is obtained for the order parameter jumps (for
molecular elongation a=3,4) with the values observed in the experiments.
This model for molecular elongation a=3 was studied in greater detail
in the presense of a 5% concentration of disordered quenched impurities,
in which case we have observed a very weak first order transition. The Monte
Carlo simulations were performed for four different lattice sizes and the
finite-size scaling analysis and the Ferrenberg-Swendsen reweighting technique
were applied to obtained data. We have discussed a shift of the transition
temperature, a suppression of the latent heat and the maxima of the heat
capacity and susceptibility due to the presence of impurities. A
comparison of the simulation data with the experimental results for liquid
crystals confined to silica aerogels and porous glasses also has been
performed. This work is done in cooperation with S.Sokolowski (Faculty of Chemistry,
MSC University, Lublin, Poland) and O.Pizio (Instituto de Quimica de la UNAM,
Coyoacan, Mexico, D.F.).
The other studies have been started recently concern behaviour of the Gay-Berne
model for anisotropic liquid with the presence of the matrix of quenched
spherical centers of different size. Both hard and soft matrix-fluid interactions
are considered and the influence of the matrix on phase behaviour of the
system is studied (together with A.Kovalenko, Institute for Molecular
Science, Myodaiji, Okazaki, Japan).
Referred papers
- I.R.Yukhnovskii, Ja.M.Ilnytskyi, M.P.Kozlovskii.
Application of the specific phase space division to
investigation of the 3D Ising model (Proc. of the
conference Modern problems of statistical physics, Kyiv,
Naukova dumka, vol.2, pp.103-108, 1989, in Russian).
- I.R.Yukhnovskii, M.P.Kozlovskii, Ja.M.Ilnytskyi. On
choosing of the renormalization group parameter in
investigation of 3D Ising model, Ukrainian physical
journal, vol.34, No.7, pp.1106-1110, 1989 (in Russian).
- Ja.M.Ilnytskyi, M.P.Kozlovskii, Theory of phase
transitions by the collective variables method: accurate
critical indices and detailed comparison with the other
approaches. Condensed Matter Physics (Lviv), Iss. 5,
pp.23-41, 1995, LaTeX.
- Ja.M.Ilnytskyi, M.P.Kozlovskii, I.R.Yukhnovskii. On the
theory of phase transitions by collective variables
method, International Journal of Modern Physics B, vol.11,
No.8, pp.1009-1022, 1997.
- Ja.M.Ilnytskyi. A study of the nematic-isotropic phase
transition in liquid crystals by Monte Carlo simulations
of lattice models, Journal of Physical Studies, vol.1, No.2, pp.232-240, 1997,
abstract,
ps.
- Ja.Ilnytskyi, Modified Lebwohl-Lasher model for investigation of
nematic-isotropic phase transition in liquid crystals, Mol. Cryst.
Liq. Cryst., vol.323, pp.113-128, 1998,
ps.
- S.Sokolowski, A.Patrykiejew, Ja.Ilnytskyi, O.Pizio, Replica Ornstein-Zernike
Equations for Polydisperse Quenched-Annealed Fluids. Hard Spheres in a
Polydisperse Disordered Hard Sphere Matrix, Journ. Phys. Chem. B, vol.103,
pp.868-871, 1999.
- Ja.M.Ilnytskyi, NEMATIC-ISOTROPIC TRANSITION IN A WEAKLY DILUTED LATTICE MODEL: MONTE CARLO STUDY,
Condensed Matter Physics, 1999, vol. 2, No. 2(18), p. 189-196,
ps.
- Ja.Ilnytskyi, S.Sokolowski, O.Pizio, Nematic-isotropic
transition in a lattice model with quenched disordered impurities.
A Monte Carlo study, Phys. Rev. E, vol.59, No.4, pp.4161-4168, 1999,
abstract,
ps.
- Ilnytskyi J, Wilson MR, A domain decomposition molecular dynamics program
for the simulation of flexible molecules with an arbitrary topology of
Lennard-Jones and/or Gay-Berne sites, COMPUTER PHYSICS COMMUNICATIONS 134
(1): 23-32 FEB 1 2001
- Ilnytskyi JM, Wilson MR, Molecular models in computer simulation of liquid crystals
JOURNAL OF MOLECULAR LIQUIDS 92 (1-2): 21-28 Sp. Iss. SI JUN 2001
- Earl DJ, Ilnytskyi J, Wilson MR, Computer simulations of soft repulsive spherocylinders
MOLECULAR PHYSICS 99 (20): 1719-1726 OCT 2001
- Ilnytskyi JM, Wilson MR, A domain decomposition molecular dynamics program for the
simulation of flexible molecules of spherically-symmetrical and nonspherical sites.
II. Extension to NVT and NPT ensembles, COMPUTER PHYSICS COMMUNICATIONS 148 (1):
43-58 OCT 1 2002
- Cuetos A, Ilnytskyi JM, Wilson MR, Rotational viscosities of Gay-Berne mesogens
MOLECULAR PHYSICS 100 (24): 3839-3845 DEC 20 2002
- Saphiannikova M, Radtchenko I, Sukhorukov G, et al., Molecular-dynamics simulations
and x-ray analysis of dye precipitates in the polyelectrolyte microcapsules,
JOURNAL OF CHEMICAL PHYSICS 118 (19): 9007-9014 MAY 15 2003
- Wilson MR, Ilnytskyi JM, Stimson LM, Computer simulations of a liquid crystalline
dendrimer in liquid crystalline solvents, JOURNAL OF CHEMICAL PHYSICS 119 (6):
3509-3515 AUG 8 2003
- Wilson M. R., Ilnytskyi J. M., Parallel computer simulation techniques for the study
of macromolecules, in Computer Simulations of liquid crystals and polymers, eds Pasini P.,
Zannoni C. and Zu(mer S., (Kluwer 2004), 335-356.
- Wilson M. R., Ilnytskyi J. M., Stimson L. M., Hughes Z. E., Computer simulations of
liquid crystal polymers and dendrimers in Computer Simulations of liquid crystals and
polymers, eds Pasini P., Zannoni C. and Zu(mer S., (Kluwer 2004), 57-78.
- Ivaneyko D, Ilnytskyi J, Berche B, et al., Criticality of the random-site Ising model:
Metropolis, Swendsen-Wang and Wolff Monte Carlo algorithms, CONDENSED MATTER PHYSICS
8 (1): 149-162 2005
- Ilnytskyi J, Saphiannikova M, Neher D, Photo-induced deformations in azobenzene-containing
side-chain polymers: molecular dynamics study, CONDENSED MATTER PHYSICS 9 (1): 87-94 2006
- Ivaneyko D, Ilnytskyi J, Berche B, et al., Static and dynamic critical behaviour of 3d
random-site Ising model: Different Monte Carlo algorithms, JOURNAL OF MOLECULAR LIQUIDS 127
(1-3): 69-70 Sp. Iss. SI AUG 15 2006
- Ivaneyko D, Ilnytskyi J, Berche B, et al., Local and cluster critical dynamics of the 3d
random-site Ising model, PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS 370 (2):
163-178 OCT 15 2006
- M.R.Wilson, L.M.Stimson, J.M.Ilnytskyi, The influence of lateral and terminal substitution
on the structure of a liquid crystal dendrimer in nematic solution: A computer simulation
study, Liquid Crystals, 33, No.10, 1167-1175, October 2006
Preprints
- M.P.Kozlovskii, Ja.M.Ilnytskyi, I.V.Pylyuk. Free energy
and other thermodynamical functions of the 3D Ising model
below the phase transition point, Ukr. Acad. Sci., Inst.
Theor. Phys.; Preprint ITP-85-107P, Kyiv, 1985 (in
Russian).
- I.R.Yukhnovskii, Ja.M.Ilnytskyi, M.P.Kozlovskii,
Investigation of the critical properties of 3D Ising
model. Specific phase space division, Ukr. Acad. Sci.,
Inst. Theor. Phys.; Preprint ITP-87-17P, Kyiv, 1987 (in
Russian).
- Ja.M.Ilnytskyi. Investigation of the critical properties
of 3D Ising model by the specific phase space division.
The higher basic distributions, Ukr. Acad. Sci., Inst.
Theor. Phys.; Preprint ITP-87-150P, Kyiv, 1987 (in
Russian).
- M.P.Kozlovskii,Ja.M.Ilnytskyi. Description of phase
transition in systems with dimensionality close to four
in the collective variables method, Ukr. Acad. Sci.,
Inst. Theor. Phys.; Preprint ITP-87-100E, Kyiv, 1988.
- M.P.Kozlovskii, Ja.M.Ilnytskyi. Non-universal
thermodynamical characteristics of the Ising model with
the dimensionality close to four in the collective
variables method, Ukr. Acad. Sci., Inst. Theor. Phys.;
Preprint ITP-88-69P, Kyiv, 1988 (in Russian).
- Ja.M.Ilnytskyi, M.P.Kozlovskii, The reexpansion
procedure. Application to the asymptotical series of the
perturbation theory, Ukr. Acad. Sci., Inst. Theor. Phys.;
Preprint ITP-90-38U, Kyiv, 1990 (in Ukrainian).
- Ja.M.Ilnytskyi. Collective variables method and the epsilon-expansion,
Ph.D. thesis, Lviv University, 1994 (in Ukrainian).
- Ja.M.Ilnytskyi. Investigation of nematic-isotropic phase
transition in liquid crystals by Monte Carlo simulations
of lattice models. Ukr. Acad. Sci., Inst. Cond. Matt.
Phys.; Preprint ICMP-97-04E, Lviv, 1997. LaTeX,
ps
- Ja. Ilnytskyi, S. Sokolowski, O. Pizio, On the nematic-isotropic
transition in a lattice model with quenched disordered impurities.
A Monte Carlo study, Ukr. Acad. Sci., Inst. Cond. Matt. Phys.;
Preprint ICMP-98-33E, Lviv, 1997.
abstract,
ps
Abstracts of talks and posters
- Ja.M.Ilnytskyi, The Reexpansion Procedure. Application to the asymptotic
series of perturbation theory (First Soviet-Polish
Symposium on Physics of Ferroelectrics, Lviv, Ukraine, 1990,
Abstracts, p.139).
- Ja.M.Ilnytskyi, M.P.Kozlovskii, Critical behaviour of the n-component model by
the approximate renormalization group transformation (Modern Problems of Statistical
Physics, Kharkiv, Ukraine, 1991, Abstracts, p.79).
- Ja.M.Ilnytskyi, M.P.Kozlovskii, Equation of state of one-component spin
model in the 3D case (Ukrainian-French Symposium "Condensed
Matter: Science and Industry" Lviv, Ukraine, 20-27 Feb.1993., Abstracts,
Information, Participants, Lviv, 1993. p.238).
- Ja.M.Ilnytskyi, Study of the nematic-isotropic phase transition in liquid crystals
by means of computer simulations of the lattice models (Seminar on Statistical
Theory of Condensed Matter, Lviv, Ukraine, 1997, Abstracts, p.121).
- Ja.M. Ilnytskyi, A study of the nematic-isotropic phase transition in liquid crystals
by Monte Carlo simulations of lattice models (MECO 22, Szklarska Poreba, Poland, 1997).
- Ja. M. Ilnytskyi, A study of the nematic-isotropic phase transition in liquid crystals
by Monte Carlo simulations of lattice models (Intas-Ukraine Workshop on Condensed Matter
Physics, Lviv, Ukraine, 21-24 May, 1998, Abstracts, p.93).
- Ja. M. Ilnytskyi, Investigation of the nematic to isotropic phase transition by means of the
modified Lebwohl-Lasher model (NATO ASI "Advances in the Computer Simulations of Liquid
Crystals", Erice, Sicily, Italy, Abstracts).
- Ja.Ilnytskyi, S.Sokolowski, O.Pizio, On the nematic-isotropic
transition in a lattice model with quenched disordered impurities.
A Monte Carlo study (The Annual Conference of the British Liquid Crystal
Society, Durham, Great Britain, 29-31 March 1999, Abstracts, P41).
- Conference "Modern Problems of Statistical
Physics", Lviv, Ukraine, 3-6 February 1987.
- Regional Conference for young scientists "The Physics
of Condensed Matter", Lviv, Ukraine, 29-30 March 1988.
- Workshop for Young Scientists on Statistical Physics,
Lviv, Ukraine, 12-15 October 1988.
- First Soviet-Polish Symposium on Physics of
Ferroelectrics, Lviv, Ukraine, 4-8 June 1990.
- International School on Nonlinear and Dynamical Systems,
Samos, Samos, Greece, July 1990.
- All-Union Conference "Modern Problems of Statistical
Physics", Kharkiv, Ukraine, 14-17 May 1991.
- International School for young scientists, Research Center of Crete,
Iraklio, Crete, Greece, July 1991.
- International School of Statistical Physics for young scientists, Slavsko,
Lviv province, Ukraine, 12-19 September 1991.
- Ukrainian-French Symposium "Condensed Matter:
Science and Industry" Lviv, Ukraine, 20-27 February 1993.
- Scientific Seminar on Statistical Theory of Condensed
Matter, Lviv University, Lviv, Ukraine, 14-15 March 1997.
- Middle European Cooperation in Statistical Physics
(MECO22), Szklarska Poreba, Poland, 3-5 April 1997.
- Intas-Ukraine Workshop on Condensed Matter Physics, Lviv, Ukraine, 21-24
May 1998.
- NATO ASI "Advances in the Computer Simulations of Liquid Crystals",
Erice, Sicily, Italy, 11-21 June 1998.
- The Annual Conference of the British Liquid Crystal Society, Durham,
Great Britain, 29-31 March 1999.
- Ph.D. degree on physics and mathematics, Lviv State University, Lviv, Ukraine (1994).
- Scientific stipend of Ukrainian National Academy of Sciences (1995).
- Personal grant from President of Ukrainan Academy of sciences (1996).
Last updated 27 Feb, 1998
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