A new class of analytic solutions in the optimal turn problem for a spherically symmetric body

2012 ◽  
Vol 47 (2) ◽  
pp. 167-177 ◽  
Author(s):  
A. V. Molodenkov ◽  
Ya. G. Sapunkov
2020 ◽  
Vol 496 (2) ◽  
pp. 1023-1034
Author(s):  
Bidzina M Shergelashvili ◽  
Velentin N Melnik ◽  
Grigol Dididze ◽  
Horst Fichtner ◽  
Günter Brenn ◽  
...  

ABSTRACT A new class of one-dimensional solar wind models is developed within the general polytropic, single-fluid hydrodynamic framework. The particular case of quasi-adiabatic radial expansion with a localized heating source is considered. We consider analytical solutions with continuous Mach number over the entire radial domain while allowing for jumps in the flow velocity, density, and temperature, provided that there exists an external source of energy in the vicinity of the critical point that supports such jumps in physical quantities. This is substantially distinct from both the standard Parker solar wind model and the original nozzle solutions, where such discontinuous solutions are not permissible. We obtain novel sample analytic solutions of the governing equations corresponding to both slow and fast winds.


2008 ◽  
Vol 74 (4) ◽  
pp. 569-573 ◽  
Author(s):  
G. ROWLANDS ◽  
G. BRODIN ◽  
L. STENFLO

AbstractLarge amplitude plasma oscillations are studied in a cold electron plasma. Using Lagrangian variables, a new class of exact analytical solutions is found. It turns out that the electric field amplitude is limited either by wave breaking or by the condition that the electron density always has to stay positive. The range of possible amplitudes is determined analytically.


1971 ◽  
Vol 38 (3) ◽  
pp. 702-705 ◽  
Author(s):  
J. M. McKinney

A solution, exact within the framework of linear elastokinetics, is obtained for a vibrating, elastic, arbitrarily thick spherical shell subject only to a spherically symmetric body force field of the form FR(r, τ) = Fr(r)Ft(τ). Fr(r) is taken in the form of a polynomial whereas Ft(τ) is restricted only to being a sectionally continuous function of time.


1988 ◽  
Vol 130 ◽  
pp. 516-516
Author(s):  
Robin M. Green ◽  
David Alexander

The presence of the cosmical constant introduces a fundamental scale and prevents there being any simple self-symmetry. Henriksen, Emslie and Wesson (HEW), who studied spherically-symmetric models with a positive cosmical constant, have, however, demonstrated the possible existence of a self-similarity of the second kind and identified the similarity variable. They obtained interesting analytic solutions which are homogeneous in density, but not in pressure. We have extended this work and investigated the general behaviour of these cosmological models which possess a self-similarity of the second kind and in which the requirement of homogeneity is relaxed.


Universe ◽  
2018 ◽  
Vol 5 (1) ◽  
pp. 8 ◽  
Author(s):  
Nikolaos E. Mavromatos ◽  
Sarben Sarkar

On extending the Standard Model (SM) Lagrangian, through a non-linear Born–Infeld (BI) hypercharge term with a parameter β (of dimensions of [mass] 2 ), a finite energy monopole solution was claimed by Arunasalam and Kobakhidze. We report on a new class of solutions within this framework that was missed in the earlier analysis. This new class was discovered on performing consistent analytic asymptotic analyses of the nonlinear differential equations describing the model; the shooting method used in numerical solutions to boundary value problems for ordinary differential equations is replaced in our approach by a method that uses diagonal Padé approximants. Our work uses the ansatz proposed by Cho and Maison to generate a static and spherically-symmetric monopole with finite energy and differs from that used in the solution of Arunasalam and Kobakhidze. Estimates of the total energy of the monopole are given, and detection prospects at colliders are briefly discussed.


2007 ◽  
Vol 16 (01) ◽  
pp. 65-79 ◽  
Author(s):  
GAMAL G. L. NASHED ◽  
TAKESHI SHIRAFUJI

We give two classes of spherically symmetric exact solutions of the coupled gravitational and electromagnetic fields with charged source in the tetrad theory of gravitation. The first solution depends on an arbitrary function H(R,t). The second solution depends on a constant parameter η. These solutions reproduce the same metric, i.e. the Reissner–Nordström metric. If the arbitrary function which characterizes the first solution and the arbitrary constant of the second solution are set to be zero, then the two exact solutions will coincide with each other. We then calculate the energy content associated with these analytic solutions using the superpotential method. In particular, we examine whether these solutions meet the condition, which Møller required for a consistent energy–momentum complex, namely, we check whether the total four-momentum of an isolated system behaves as a four-vector under Lorentz transformations. It is then found that the arbitrary function should decrease faster than [Formula: see text] for R → ∞. It is also shown that the second exact solution meets the Møller's condition.


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