scholarly journals Development of singularities of the Skyrme model

2020 ◽  
Vol 17 (01) ◽  
pp. 61-73
Author(s):  
Michael McNulty
Keyword(s):  
Sigma Model ◽  
Blow Up ◽  
Strong Field ◽  
Skyrme Model ◽  
Nonlinear Sigma Model ◽  
Field Limit ◽  
Wave Maps ◽  
Self Similar ◽  
Similar Solutions ◽  
Strong Field Limit

The Skyrme model is a geometric field theory and a quasilinear modification of the Nonlinear Sigma Model (Wave Maps). In this paper, we study the development of singularities for the equivariant Skyrme Model, in the strong-field limit, where the restoration of scale invariance allows us to look for self-similar blow-up behavior. After introducing the Skyrme Model and reviewing what’s known about formation of singularities in equivariant Wave Maps, we prove the existence of smooth self-similar solutions to the [Formula: see text]-dimensional Skyrme Model in the strong-field limit, and use that to conclude that the solution to the corresponding Cauchy problem blows-up in finite time, starting from a particular class of everywhere smooth initial data.

scholarly journals Perturbative deflection angle, gravitational lensing in the strong field limit and the black hole shadow

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Junji Jia ◽  
Ke Huang
Keyword(s):  
Gravitational Lensing ◽  
Deflection Angle ◽  
Strong Field ◽  
Distance Effect ◽  
Critical Value ◽  
Field Limit ◽  
Perturbative Method ◽  
The Deflection Angle ◽  
The Impact ◽  
Strong Field Limit

AbstractA perturbative method to compute the deflection angle of both timelike and null rays in arbitrary static and spherically symmetric spacetimes in the strong field limit is proposed. The result takes a quasi-series form of $$(1-b_c/b)$$ ( 1 - b c / b ) where b is the impact parameter and $$b_c$$ b c is its critical value, with coefficients of the series explicitly given. This result also naturally takes into account the finite distance effect of both the source and detector, and allows to solve the apparent angles of the relativistic images in a more precise way. From this, the BH angular shadow size is expressed as a simple formula containing metric functions and particle/photon sphere radius. The magnification of the relativistic images were shown to diverge at different values of the source-detector angular coordinate difference, depending on the relation between the source and detector distance from the lens. To verify all these results, we then applied them to the Hayward BH spacetime, concentrating on the effects of its charge parameter l and the asymptotic velocity v of the signal. The BH shadow size were found to decrease slightly as l increases to its critical value, and increase as v decreases from light speed. For the deflection angle and the magnification of the images however, both the increase of l and decrease of v will increase their values.

scholarly journals Examples of non connective C *-algebras

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Anna Gąsior ◽  
Andrzej Szczepański
Keyword(s):  
Fixed Point ◽  
Existence And Uniqueness ◽  
Fixed Point Theorems ◽  
Blow Up ◽  
Fractional Diffusion ◽  
Uniqueness Of Solutions ◽  
C Algebras ◽  
Space Fractional Diffusion Equation ◽  
Self Similar ◽  
Similar Solutions

Abstract This paper investigates the problem of the existence and uniqueness of solutions under the generalized self-similar forms to the space-fractional diffusion equation. Therefore, through applying the properties of Schauder’s and Banach’s fixed point theorems; we establish several results on the global existence and blow-up of generalized self-similar solutions to this equation.

scholarly journals Self-Similar Blow-Up Solutions of the KPZ Equation

2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
Alexander Gladkov
Keyword(s):  
Asymptotic Behavior ◽  
Blow Up ◽  
Kpz Equation ◽  
Self Similar ◽  
The Kpz Equation ◽  
Similar Solutions

Self-similar blow-up solutions for the generalized deterministic KPZ equationut=uxx+|ux|qwithq>2are considered. The asymptotic behavior of self-similar solutions is studied.

scholarly journals SKYRME MODEL ON S3 AND HARMONIC MAPS

1999 ◽  
Vol 14 (14) ◽  
pp. 893-901 ◽  
Author(s):  
Y. BRIHAYE ◽  
C. GABRIEL
Keyword(s):  
Sigma Model ◽  
Harmonic Maps ◽  
Skyrme Model ◽  
Critical Values ◽  
Classical Solutions ◽  
Nonlinear Sigma Model ◽  
Coupling Constant

A nonlinear sigma model mimicking the Skyrme model on S3 is proposed and a family of classical solutions to the equations are constructed numerically. The solutions terminate into catastrophic-like spikes at critical values of the Skyrme coupling constant and, when this constant is zero, they coincide with the series of harmonic maps on S3 constructed some years ago by P. Bizon.

On Uniqueness and Stability of Self-Similar Blow-Up Solutions of Nonlinear Heat Equations: Evolution Approach

2003 ◽  
Vol 05 (03) ◽  
pp. 329-348 ◽  
Author(s):  
Manuela Chaves ◽  
Victor A. Galaktionov
Keyword(s):  
Parabolic Equations ◽  
Blow Up ◽  
Domain Of Attraction ◽  
Nonlinear Parabolic Equations ◽  
Heat Equations ◽  
Nonlinear Parabolic ◽  
Linear Parabolic Equations ◽  
Self Similar ◽  
Similar Solutions ◽  
Evolution Approach

We present evolution arguments of studying uniqueness and asymptotic stability of blow-up self-similar solutions of second-order nonlinear parabolic equations from combustion and filtration theory. The analysis uses intersection comparison techniques based on the Sturm Theorem on zero set for linear parabolic equations. We show that both uniqueness and stability of similarity ODE profiles are directly related to the asymptotic structure of their domain of attraction relative to the corresponding parabolic evolution.

scholarly journals Some Remarks on Nonlinear Electrodynamics

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Patricio Gaete
Keyword(s):  
Interaction Energy ◽  
Long Range ◽  
Coulomb Potential ◽  
Strong Field ◽  
Nonlinear Electrodynamics ◽  
Field Limit ◽  
Logarithmic Order ◽  
Heisenberg Type ◽  
Path Dependent ◽  
Strong Field Limit

By using the gauge-invariant, but path-dependent, variables formalism, we study both massive Euler-Heisenberg-like and Euler-Heisenberg-like electrodynamics in the approximation of the strong-field limit. It is shown that massive Euler-Heisenberg-type electrodynamics displays the vacuum birefringence phenomenon. Subsequently, we calculate the lowest-order modifications to the interaction energy for both classes of electrodynamics. As a result, for the case of massive Euler-Heisenbeg-like electrodynamics (Wichmann-Kroll), unexpected features are found. We obtain a new long-range (1/r3-type) correction, apart from a long-range(1/r5-type) correction to the Coulomb potential. Furthermore, Euler-Heisenberg-like electrodynamics in the approximation of the strong-field limit (to the leading logarithmic order) displays a long-range (1/r5-type) correction to the Coulomb potential. Besides, for their noncommutative versions, the interaction energy is ultraviolet finite.

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