Paweł Węgrzyn - Academia.edu (original) (raw)
Papers by Paweł Węgrzyn
Lecture notes in computer science, 2024
Bio-Algorithms and Med-Systems, 2009
Physics Letters B, Oct 1, 1991
Abstract We derive the identities originating from the reparametrization invariance in the classi... more Abstract We derive the identities originating from the reparametrization invariance in the classical string theory. Next we use them to analyse the edge conditions to the equations of motion for the open string with rigidity.
Bio-inspired Systems and Applications: from Robotics to Ambient Intelligence
Time evolution of hoop-like configurations of the classical string with rigidity is studied. Emph... more Time evolution of hoop-like configurations of the classical string with rigidity is studied. Emphasis is put on effects which are due to the presence of higher derivatives in the theory. Trajectories close to Nambu-Goto trajectories and tachyonic trajectories of the string are found. It is pointed out that the dynamics of the hoop-like string with rigidity is probably non-integrable
Acta Physica Polonica B, 1989
Systematic analysis of classical trajectories of a point-like analogue of the smooth string is pr... more Systematic analysis of classical trajectories of a point-like analogue of the smooth string is presented. It is shown that the point-like analogue contains tachyons on the classical level
Physical review D: Particles and fields
ABSTRACT
Physics Letters B, 1992
It is pointed out that the effective action method, which was recently used in studies of dynamic... more It is pointed out that the effective action method, which was recently used in studies of dynamics of a vortex, yields lagrangians which in general are nonlocal and contain higher derivatives. The origin of apparently pathological features of an effective model of vortex dynamics, known as the string with rigidity model, is suggested.
Physical Review D, 1994
Classical bosonic open string models in four-dimensional Minkowski spacetime are discussed. A spe... more Classical bosonic open string models in four-dimensional Minkowski spacetime are discussed. A special attention is paid to the choice of edge conditions, which can follow consistently from the action principle. We consider lagrangians that can depend on second order derivatives of worldsheet coordinates. A revised interpretation of the variational problem for such string theories is given. We derive a general form of a boundary term that can be added to the open string action to control edge conditions and modify conservation laws. An extended boundary problem for minimal surfaces is examined. Following the treatment of this model in the geometric approach, we obtain that classical open string states correspond to solutions of a complex Liouville equation. In contrast to the Nambu-Goto case, the Liouville potential is finite and constant at worldsheet boundaries. The phase part of the potential defines topological sectors of solutions.
Modern Physics Letters A, 1996
We examine the relativistic Nambu-Goto model with Gauss-Bonnet boundary term added to the action ... more We examine the relativistic Nambu-Goto model with Gauss-Bonnet boundary term added to the action integral. The dynamical system is analyzed using an invariant representation of string degrees of freedom by complex Liouville fields. The solutions of classical equations of motion for open strings are described.
Modern Physics Letters A, 1996
At the classical level we study open bosonic strings. A generic description of string self-intera... more At the classical level we study open bosonic strings. A generic description of string self-interactions localized at string ends is given. Self-interactions are characterized by two dimensionless coupling constants. The model is rewritten using complex Liouville fields. Using these Lorentz and reparametrization invariant variables, equations of motion get greatly simplified and reduce to some boundary problem for Liouville equation. Henceforth, the Nambu-Goto string model is proved to be still rnathematically tractable if we attach finite masses and interactions at string end points. With the help of semiclassical quantization, we indicate several encouraging points for hadronic strings.
Modern Physics Letters A, 1996
The problem of meson bound states with Nf massive fermions in two-dimensional quantum electrodyna... more The problem of meson bound states with Nf massive fermions in two-dimensional quantum electrodynamics is discussed. We monitor the spectrum of the lightest particles by means of the effective semiclassical description. In particular, the systems of fundamental fermions with SU(2) and SU(3) flavor symmetries broken by massive terms are investigated.
Modern Physics Letters A, 2004
We discuss the quantized field inside a general one-dimensional cavity system. We recognize the S... more We discuss the quantized field inside a general one-dimensional cavity system. We recognize the SL (2,R) symmetry being the remainder of the conformal group. The explanation of the lack of the resonance production for the fundamental frequency is given and the asymptotic behavior of the cavity system is properly described.
Journal of Physics B: Atomic, Molecular and Optical Physics, 2007
Journal of Physics B: Atomic, Molecular and Optical Physics, 2006
We recently proposed a new approach to analyze the parametric resonance in a vibrating cavity bas... more We recently proposed a new approach to analyze the parametric resonance in a vibrating cavity based on the analysis of classical optical paths. This approach is used to examine various models of cavities with moving walls. We prove that our method is useful to extract easily basic physical outcome.
Acta Physica Polonica B, 2003
ABSTRACT
Lecture notes in computer science, 2024
Bio-Algorithms and Med-Systems, 2009
Physics Letters B, Oct 1, 1991
Abstract We derive the identities originating from the reparametrization invariance in the classi... more Abstract We derive the identities originating from the reparametrization invariance in the classical string theory. Next we use them to analyse the edge conditions to the equations of motion for the open string with rigidity.
Bio-inspired Systems and Applications: from Robotics to Ambient Intelligence
Time evolution of hoop-like configurations of the classical string with rigidity is studied. Emph... more Time evolution of hoop-like configurations of the classical string with rigidity is studied. Emphasis is put on effects which are due to the presence of higher derivatives in the theory. Trajectories close to Nambu-Goto trajectories and tachyonic trajectories of the string are found. It is pointed out that the dynamics of the hoop-like string with rigidity is probably non-integrable
Acta Physica Polonica B, 1989
Systematic analysis of classical trajectories of a point-like analogue of the smooth string is pr... more Systematic analysis of classical trajectories of a point-like analogue of the smooth string is presented. It is shown that the point-like analogue contains tachyons on the classical level
Physical review D: Particles and fields
ABSTRACT
Physics Letters B, 1992
It is pointed out that the effective action method, which was recently used in studies of dynamic... more It is pointed out that the effective action method, which was recently used in studies of dynamics of a vortex, yields lagrangians which in general are nonlocal and contain higher derivatives. The origin of apparently pathological features of an effective model of vortex dynamics, known as the string with rigidity model, is suggested.
Physical Review D, 1994
Classical bosonic open string models in four-dimensional Minkowski spacetime are discussed. A spe... more Classical bosonic open string models in four-dimensional Minkowski spacetime are discussed. A special attention is paid to the choice of edge conditions, which can follow consistently from the action principle. We consider lagrangians that can depend on second order derivatives of worldsheet coordinates. A revised interpretation of the variational problem for such string theories is given. We derive a general form of a boundary term that can be added to the open string action to control edge conditions and modify conservation laws. An extended boundary problem for minimal surfaces is examined. Following the treatment of this model in the geometric approach, we obtain that classical open string states correspond to solutions of a complex Liouville equation. In contrast to the Nambu-Goto case, the Liouville potential is finite and constant at worldsheet boundaries. The phase part of the potential defines topological sectors of solutions.
Modern Physics Letters A, 1996
We examine the relativistic Nambu-Goto model with Gauss-Bonnet boundary term added to the action ... more We examine the relativistic Nambu-Goto model with Gauss-Bonnet boundary term added to the action integral. The dynamical system is analyzed using an invariant representation of string degrees of freedom by complex Liouville fields. The solutions of classical equations of motion for open strings are described.
Modern Physics Letters A, 1996
At the classical level we study open bosonic strings. A generic description of string self-intera... more At the classical level we study open bosonic strings. A generic description of string self-interactions localized at string ends is given. Self-interactions are characterized by two dimensionless coupling constants. The model is rewritten using complex Liouville fields. Using these Lorentz and reparametrization invariant variables, equations of motion get greatly simplified and reduce to some boundary problem for Liouville equation. Henceforth, the Nambu-Goto string model is proved to be still rnathematically tractable if we attach finite masses and interactions at string end points. With the help of semiclassical quantization, we indicate several encouraging points for hadronic strings.
Modern Physics Letters A, 1996
The problem of meson bound states with Nf massive fermions in two-dimensional quantum electrodyna... more The problem of meson bound states with Nf massive fermions in two-dimensional quantum electrodynamics is discussed. We monitor the spectrum of the lightest particles by means of the effective semiclassical description. In particular, the systems of fundamental fermions with SU(2) and SU(3) flavor symmetries broken by massive terms are investigated.
Modern Physics Letters A, 2004
We discuss the quantized field inside a general one-dimensional cavity system. We recognize the S... more We discuss the quantized field inside a general one-dimensional cavity system. We recognize the SL (2,R) symmetry being the remainder of the conformal group. The explanation of the lack of the resonance production for the fundamental frequency is given and the asymptotic behavior of the cavity system is properly described.
Journal of Physics B: Atomic, Molecular and Optical Physics, 2007
Journal of Physics B: Atomic, Molecular and Optical Physics, 2006
We recently proposed a new approach to analyze the parametric resonance in a vibrating cavity bas... more We recently proposed a new approach to analyze the parametric resonance in a vibrating cavity based on the analysis of classical optical paths. This approach is used to examine various models of cavities with moving walls. We prove that our method is useful to extract easily basic physical outcome.
Acta Physica Polonica B, 2003
ABSTRACT