Zobrazeno 1 - 10
of 52
pro vyhledávání: '"John Carminati"'
Autor:
Norbert Van den Bergh, John Carminati
Publikováno v:
CLASSICAL AND QUANTUM GRAVITY
We discuss Petrov type D Einstein-Maxwell fields in which both double null eigenvectors of the Weyl tensor are non-aligned with the eigenvectors of a non-null electromagnetic field and are assumed to be geodesic, shear-free, diverging and non-twistin
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6cd52b7aa970bc854a51a5aef7f8ce69
https://doi.org/10.1088/1361-6382/abbba3
https://doi.org/10.1088/1361-6382/abbba3
Autor:
P. A. Huf, John Carminati
Publikováno v:
General Relativity and Gravitation. 50
In this paper we explore the use of a new algebraic software package in providing independent covariant proof of a conjecture in general relativity. We examine the proof of two sub-cases of the shear-free conjecture $$\displaystyle \sigma =0 {\displa
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::503d7e5e80f3ec20bf18f7e4858f52b2
https://doi.org/10.1007/s10714-017-2325-5
https://doi.org/10.1007/s10714-017-2325-5
Autor:
G.F. Jefferson, John Carminati
Publikováno v:
Communications in Nonlinear Science and Numerical Simulation. 19:431-441
A new method for finding contact symmetries is proposed for both ordinary and partial differential equations. Symmetries more general than Lie point are often difficult to find owing to an increased dependency of the infinitesimal functions on differ
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::7db014a2cbc395ce6f0afa80f6e2449d
https://doi.org/10.1016/j.cnsns.2013.07.013
https://doi.org/10.1016/j.cnsns.2013.07.013
Autor:
John Carminati, G.F. Jefferson
Publikováno v:
Computer Physics Communications. 185:430-441
In this paper, we present an algorithm for the systematic calculation of Lie point symmetries for fractional order differential equations (FDEs) using the method as described by Buckwar & Luchko (1998) and Gazizov, Kasatkin & Lukashchuk (2007, 2009,
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1719cb622dd8c5a804df4340cba2fc51
https://doi.org/10.1016/j.cpc.2013.09.019
https://doi.org/10.1016/j.cpc.2013.09.019
Publikováno v:
Analysis and Mathematical Physics. 3:375-391
A class of non-stationary exact solutions of two-dimensional nonlinear Navier–Stokes (NS) equations within a thin rotating spherical shell were found as invariant and approximately invariant solutions. The model is used to describe a simple zonally
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::edabc59fdc6e24d6958f331851b5de31
https://doi.org/10.1007/s13324-013-0062-9
https://doi.org/10.1007/s13324-013-0062-9
Publikováno v:
International Journal of Non-Linear Mechanics. 51:28-44
The exact solutions of three-dimensional equations of motion for internal gravity waves in cylindrical coordinates in unbounded media are found by means of approximate transformation groups of equations with a small parameter. Introduction of the sma
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::b921ac54f583b1d69b9ae446fe76470a
https://doi.org/10.1016/j.ijnonlinmec.2012.12.001
https://doi.org/10.1016/j.ijnonlinmec.2012.12.001
Autor:
G.F. Jefferson, John Carminati
Publikováno v:
Computer Physics Communications. 184:1045-1063
A recent paper (Pakdemirli et al. (2004) [12] ) compared three methods of determining approximate symmetries of differential equations. Two of these methods are well known and involve either a perturbation of the classical Lie symmetry generator of t
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::3f5f0f60dd418bcf6fcd2f2241c363c0
https://doi.org/10.1016/j.cpc.2012.11.012
https://doi.org/10.1016/j.cpc.2012.11.012
Publikováno v:
Computer Physics Communications. 183:1044-1054
We present and describe, with illustrative examples, the MAPLE computer algebra package DESOLVII, which is a major upgrade of DESOLV. DESOLVII now includes new routines allowing the determination of higher symmetries (contact and Lie–Backlund) for
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e304ed73f9079fde23a1cebf8b6c9ce7
https://doi.org/10.1016/j.cpc.2012.01.005
https://doi.org/10.1016/j.cpc.2012.01.005
Publikováno v:
Classical and Quantum Gravity. 24:3735-3744
We show that shearfree perfect fluids obeying an equation of state p=(gamma -1) mu are non-rotating or non-expanding under the assumption that the spatial divergence of the magnetic part of the Weyl tensor is zero.
11 pages
11 pages
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3787a96519b94798c3bb5532ac94ed43
https://doi.org/10.1088/0264-9381/24/14/012
https://doi.org/10.1088/0264-9381/24/14/012
Publikováno v:
Computer Physics Communications. 176:682-693
We present and describe new reduction routines included in DESOLV which, in many cases, may allow the complete automation of the determination of similarity solutions of partial differential equations.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e27468d3d3bfd3f81d868ff61381712c
https://doi.org/10.1016/j.cpc.2007.03.005
https://doi.org/10.1016/j.cpc.2007.03.005