14 citations · 112 across the 25 of their papers we have counts for
25 papers
Magnetic contribution to outer-disk rotation in the spiral galaxy NGC 5055
Natalia Woźniak, Joanna Jałocha, Łukasz Bratek +1
We test whether fields of galactic strength enhance NGC~5055's outer gas rotation. Finite analytic disk decompositions yield consistent rotation--density pairs and a blended gravit…
On the issue of magnetic monopoles in the prospect of UHE photon searches
Łukasz Bratek, Joanna Jałocha
(also inside: this manuscript introduces the reader to the argument against the existence of magnetic monopoles, which forms an essential part of Staruszkiewicz's Quantum Mechanics…
Cylindrically symmetric radial accretion onto a Levi-Civita string-like source
Łukasz Bratek, Joanna Jałocha, Marek Kutschera
Radial steady-state accretion of polytropic matter is investigated under cylindrical symmetry in the Levi-Civita background metric. The model can be considered as a cylindrical ana…
Cosmic-Ray Extremely Distributed Observatory: a global cosmic ray detection framework
O. Sushchov, P. Homola, N. Dhital +19
The main objective of the Cosmic-Ray Extremely Distributed Observatory (CREDO) is the detection and analysis of extended cosmic ray phenomena, so-called super-preshowers (SPS), usi…
The Havriliak-Negami relaxation and its relatives: the response, relaxation and probability density functions
K. Górska, A. Horzela, Ł. Bratek +2
We study functions related to the experimentally observed Havriliak-Negami dielectric relaxation pattern in the frequency domain with being some…
Magnetic flux density from the relative circular motion of stars and partially ionized gas in the Galaxy mid-plane vicinity
Joanna Jałocha, Łukasz Bratek, Jan Pękala +2
Observations suggest a slower stellar rotation relative to gas rotation in the outer part of the Milky Way Galaxy. This difference could be attributed to an interaction with the in…
Velocity dispersion as a factor modifying the distribution of mass in disk-like galaxies -- an example of galaxy UGC 6446
Szymon Sikora, Łukasz Bratek, Joanna Jałocha +1
Within the disk model framework used to approximately describe flattened galaxies, we develop an iterative method of determining column mass density from rotation curve supplemente…
Relativistic Ideal Clock
Łukasz Bratek
Two particularly simple ideal clocks exhibiting intrinsic circular motion with the speed of light and opposite spin alignment are described. The clocks are singled out by singulari…
Velocity-density twin transforms in thin disk model
Łukasz Bratek, Szymon Sikora, Joanna Jałocha +1
Ring mass density and the corresponding circular velocity in thin disk model are known to be integral transforms of one another. But it may be less familiar that the transforms can…
Motion of halo compact objects in the gravitational potential of a low-mass model of the Galaxy
Szymon Sikora, Łukasz Bratek, Joanna Jałocha +1
Recently, we determined a lower bound for the Milky Way mass in a point mass approximation. This result was obtained for most general spherically symmetric phase-space distribution…
Constraining the vertical structure of the Milky Way rotation by microlensing in a finite-width global disk model
Joanna Jałocha, Szymon Sikora, Łukasz Bratek +1
In this paper we model the vertical structure of mass distribution of the Milky Way galaxy in the framework of a finite-width global disk model. Assuming the Galactic rotation curv…
A possible influence of magnetic fields on the rotation of gas in NGC 253
Joanna Jałocha, Łukasz Bratek, Jan Pȩkala +1
The magnetic fields that are present in the galaxy NGC 253 are exceptionally strong. This means that they can influence the rotation of matter and hence the mass-to-light ratio. In…
Spinor particle. An indeterminacy in the motion of relativistic dynamical systems with separately fixed mass and spin
Łukasz Bratek
We give an argument that a broad class of geometric models of spinning relativistic particles with Casimir mass and spin being separately fixed parameters, have indeterminate world…
The role of large-scale magnetic fields in galaxy NGC 891. Can magnetic fields help to reduce the local mass-to-light ratio in the galactic outskirts?
Joanna Jałocha, Łukasz Bratek, Jan Pȩkala +1
We address the problem of the influence of large-scale magnetic fields on galactic rotation for the example of the spiral galaxy NGC 891. Based on its rotation curve and the surfac…
A lower bound on the Milky Way mass from general phase-space distribution function models
Łukasz Bratek, Szymon Sikora, Joanna Jałocha +1
We model the phase-space of the kinematic tracers using general, smooth distribution functions to derive a conservative lower bound on the total mass within 150-200 kpc. By approxi…
Gravitational microlensing as a test of a finite-width disk model of the Galaxy
Szymon Sikora, Łukasz Bratek, Joanna Jałocha +1
The aim of this work is to show, in the framework of a simple finite-width disk model, that the amount of mass seen through gravitational microlensing measurements in the region $0…
Can rapidity become a gauge variable? Dirac Hamiltonian method and Relativistic Rotators
Łukasz Bratek
The minimal Hamiltonian for a family of relativistic rotators is constructed by a direct application of the Dirac procedure for constrained systems. The Hamiltonian equations can b…
Fundamental Relativistic Rotator. Hessian singularity and the issue of the minimal interaction with electromagnetic field
Łukasz Bratek
There are two relativistic rotators with Casimir invariants of the Poincaré group being fixed parameters. The particular models of spinning particles were studied in the past both…
Vertical gradients of azimuthal velocity in a global thin disk model of spiral galaxies NGC 2403, NGC 4559, NGC 4302 and NGC 5775
Joanna Jałocha, Łukasz Bratek, Marek Kutschera +1
We estimate the vertical gradient of rotational velocity for several spiral galaxies in the framework of a global thin-disc model, using the approximation of quasi-circular orbits.…
False constraints. A toy model for studying dynamical systems with degenerate Hessian form
Łukasz Bratek
This paper studies various aspects of the motion of relativistic rotators, both in the presence and absence of external fields, using a toy model which, in a sense, can be regarded…
Transverse gradients of azimuthal velocity in a global disk model of the Milky Way
Joanna Jałocha, Łukasz Bratek, Marek Kutschera +1
In this paper, we aim to estimate the vertical gradients in the rotational velocity of the Galaxy. This is carried out in the framework of a global thin disc model approximation. T…
Modified relativistic rotator. Toward classical Fundamental Dynamical Systems consisting of a worldline and a single spinor
Łukasz Bratek
The Author shows how to construct a class of Lagrangians for relativistic dynamical systems described by position and a single spinor. One arrives to it by imposing three requireme…
Breathing Relativistic Rotators and Fundamental Dynamical Systems
Łukasz Bratek
Recently, it was shown, that the mechanical model of a massive spinning particle proposed by Kuzenko, Lyakhovich and Segal in 1994, which is also the fundamental relativistic rotat…
On the axisymmetric thin disk model of flattened galaxies
Łukasz Bratek, Joanna Jałocha, Marek Kutschera
Non-monotonic features of rotation curves, and also the related gravitational effects typical of thin disks -- like backward-reaction or amplification of rotation by negative surfa…