31 research outputs found
Strictly finite range forces from the signum-Gordon field: exact results in two spatial dimensions
Exact formula for the force between two identical static point charges
coupled to the nonlinear scalar field of two-dimensional signum-Gordon model is
obtained. Pertinent solution of the field equation is found in the form of
one-dimensional integral. The force exactly vanishes when the distance between
the charges exceeds certain critical value.Comment: published versio
On relativistic quantum mechanics of the Majorana particle : quaternions, paired plane waves, and orthogonal representations of the Poincaré group
The standard momentum operator −i∇ has the trivial domain (the null vector) if the L2 Hilbert space consists of only real-valued functions. In consequence, it is useless in quantum mechanics of the relativistic Majorana particle which is formulated in such a Hilbert space. Instead, one can consider the axial momentum operator introduced in (2019) Phys. Lett. A 383 1242. In the present paper we report several new results which elucidate usability of the axial momentum observable. First, a new motivation for the axial momentum is given, and the Heisenberg uncertainty relation checked. Next, we show that the general solution of time evolution equation written in the axial momentum basis has a connection with quaternions. Furthermore, it turns out that in the case of massive Majorana particles, single traveling monochromatic plane waves are not possible, but there exist solutions which have the form of two plane waves traveling in opposite directions. Another issue discussed here in detail is relativistic invariance. A single real, orthogonal and irreducible representation of the Poincaré group—consistent with the lack of antiparticle—is unveiled
Spinning Q-balls in the complex signum-Gordon model
Rotational excitations of compact Q-balls in the complex signum-Gordon model
in 2+1 dimensions are investigated. We find that almost all such spinning
Q-balls have the form of a ring of strictly finite width. In the limit of large
angular momentum M_z their energy is proportional to |M_z|^(1/5).Comment: 10 page
Note on scale invariance and self-similar evolution in (3+1)-dimensional signum-gordon model
Several classes of self-similar, spherically symmetric solutions of relativistic wave equation with a nonlinear term of the form sign() are presented. They are constructed from cubic polynomials in the scale invariant variable t/r. One class of solutions describes the process of wiping out the initial field, another an accumulation of field energy in a finite and growing region of space
System ochrony poczty elektronicznej wykorzystujący oprogramowanie PGP
W artykule przdstawiona została propozycja konfiguracji oprogramowania PGP, które służy do zabezpieczania wiadomości poczty elektronicznej oraz zapewnia mechanizmy bezpiecznego dystrybuowania kluczy publicznych
Increasing resolution of digital images using edge-based approach
W artykule zostały opisane i porównane metody podwyższania rozdzielczości obrazów cyfrowych. Przedstawiono klasyfikację tych metod oraz implementacje wybranych algorytmów. Zasadniczą część artykułu stanowi przedstawienie dwóch hybrydowych autorskich metod interpolacji. Zaproponowane metody, w celu poprawy jakości interpolowanego obrazu (w szczególności jego ostrości), wykorzystują informacje o krawędziach wykrytych na obrazie oryginalnym. Artykuł opisuje, w jaki sposób są wykrywane i wykorzystywane krawędzie do poprawy jakości obrazu w większej rozdzielczości.This paper presents results of our research aiming at obtaining new methods for increasing resolution of digital images, giving better visual results. Classification of these methods and implementation of some algorithms is also shortly presented here. The main part of the paper presents two proposes a simple but efficient method for increasing resolution of digital images using edge-based approach
Swaying oscillons in the signum-Gordon model
We present a new class of oscillons in the (1+1)-dimensional signum-Gordon model. The oscillons periodically move to and fro in space. They have finite total energy, finite size, and are strictly periodic in time. The corresponding solutions of the scalar field equation are explicitly constructed from the second order polynomials in the time and position coordinates
GRE tunneling usability for IPv4 and IPv6 networks integration
W artykule opisano tunelowanie GRE (Generic Routing Encapsulation), które jest używane jako jedna z metod integracji sieci IPv4 i IPv6. Przedstawiono zasady jego działania, konfiguracji oraz ocenę wydajności tego tunelowania w odniesieniu do innych alternatywnych metod integracji sieci IPv4 i IPv6. Przebadano dwa warianty wzajemnego ułożenia sieci IPv4 i IPv6. W pierwszym przypadku "wyspy IPv6" komunikowały się przez środowisko IPv4, a w drugim "wyspy IPv4" komunikowały się przez środowisko IPv6.This paper considers GRE (Generic Routing Encapsulation) tunneling used as one of the methods of IPv4 and IPv6 networks integration. GRE tunnel operating rules, GRE tunnel configuration methods and GRE tunneling performance estimation in comparison to other IPv4 and IPv6 networks integration methods are described. Two variants of network IPv4 and IPv6 localizations were get into consideration. In the fist case, the "IPv6 islands" was connected by IPv4 environment, and in other case the "IPv4 islands" was connected by IPv6 environment