Results 31 to 40 of about 546,512 (289)

Cosmological perturbation spectra from SL(4,R)-invariant effective actions [PDF]

, 2000
We investigate four-dimensional cosmological vacuum solutions derived from an effective action invariant under global SL(n,R) transformations. We find the general solutions for linear axion field perturbations about homogeneous dilaton-moduli-vacuum ...
A. Buonanno, A. D. Linde, A. Feinstein, A. Melchiorri, A. R. Liddle, A. Shapere, B. Allen, D. V. Gal’tsov, D. Wands, David Wands, E. Cremmer, E. J. Copeland, E. J. Copeland, E. J. Copeland, E. J. Copeland, E. J. Copeland, E. J. Copeland, G. Veneziano, Helen A. Bridgman, K. Meissner, L. A. Kofman, L. A. Kofman, M. Gasperini, M. Gasperini, M. Gasperini, N. D. Birrel, R. Brustein, R. Brustein, R. Brustein, R. Brustein, R. Brustein, R. Brustein, R. Durrer, R. Durrer   +33 more
core   +2 more sources

DUALITY INVARIANCE OF COSMOLOGICAL SOLUTIONS WITH TORSION [PDF]

International Journal of Modern Physics A, 1999
We show that for a string moving in a background consisting of maximally symmetric gravity, dilaton field and second rank antisymmetric tensor field, the O(d) ⊗ O(d) transformation on the vacuum solutions gives inequivalent solutions that are not maximally symmetric.
Gangopadhyay, Debashis, Sengupta, Soumitra   +1 more
openaire   +3 more sources

Self-tuning flat domain walls in 5d gravity and string theory [PDF]

, 2000
We present Poincare invariant domain wall (``3-brane'') solutions to some 5-dimensional effective theories which can arise naturally in string theory. In particular, we find theories where Poincare invariant solutions exist for arbitrary values of the ...
A. Klemm, A. Lukas, A. Strominger, E. Verlinde, E. Witten, E. Witten, E. Witten, E. Witten, Eva Silverstein, I. Antoniadis, J. Maldacena, J. Polchinski, L. Dixon, L. Randall, M. Cvetic, M. Gremm, Michael Schulz, N. Arkani-Hamed, N. Bahcall, N. Kaloper, N. Seiberg, P. Aspinwall, P. Horava, S. de Alwis, S. Gubser, S. Kachru, S. Kachru, S. Kachru, S. Kachru, Shamit Kachru, V. Rubakov, W. Goldberger, Z. Kakushadze   +32 more
core   +2 more sources

The Compatibility of Some Integrability Methods and Related Solutions for the Variable Coefficients Geophysical KdV Model

Axioms
This paper focuses on the variable coefficients geophysical KdV (VCGKdV) equation, which involves time-dependent perturbation, nonlinearity and dispersion parameters.
Rodica Cimpoiasu, Radu Constantinescu, Corina Nicoleta Babalic   +2 more
doaj   +1 more source

A refined invariant subspace method and applications to evolution equations

, 2012
The invariant subspace method is refined to present more unity and more diversity of exact solutions to evolution equations. The key idea is to take subspaces of solutions to linear ordinary differential equations as invariant subspaces that evolution ...
A. S. Fokas, C. R. Zhu, C. X. Li, C. Z. Qu, C. Z. Qu, C. Z. Qu, G. W. Bluman, J. R. King, L. Debnath, P. J. Olver, R. Hirota, R. Hirota, R. Z. Zhdanov, S. F. Shen, S. R. Svirshchevskii, S. R. Svirshchevskii, S. S. Titov, V. A. Galaktionov, V. A. Galaktionov, W. X. Ma, W. X. Ma, W. X. Ma, W. X. Ma, W. X. Ma, W. X. Ma, W. X. Ma, W. X. Ma, W.X. Ma, Wen-Xiu Ma   +28 more
core   +1 more source

Invariant Solutions for Soil Water Equations

Mathematical and Computational Applications, 1999
We obtain exact solutions for a class of nonlinear partial differential equations which models soil water infiltration and redistribution in a bedded soil profile irrigated by a drip irrigation system. The solutions obtained are invariant under two parameter symmetry groups.
Baikov, V., Khalique, C.
openaire   +1 more source

Invariant Solutions and Conservation Laws of the (2 + 1)-Dimensional Boussinesq Equation

Abstract and Applied Analysis, 2014
Invariant solutions and conservation laws of the (2 + 1)-dimensional Boussinesq equation are studied. The Lie symmetry approach is used to obtain the invariant solutions.
Wenjuan Rui, Peiyi Zhao, Yufeng Zhang
doaj   +1 more source

Gravitational fields with a non Abelian bidimensional Lie algebra of symmetries [PDF]

, 2001
Vacuum gravitational fields invariant for a bidimensional non Abelian Lie algebra of Killing fields, are explicitly described. They are parameterized either by solutions of a transcendental equation (the tortoise equation) or by solutions of a linear ...
A.M. Vinogradov, Aliev, Belinsky, Belinsky, Belinsky, Chinea, Einstein, G. Sparano, G. Vilasi, Geroch, Hallisoy, Kompaneyets, Kramer, Petrov, Rosen, Sparano, Verdaguer, Vinogradov, Wald   +18 more
core   +2 more sources

Financial Burden Associated With Hospitalisation Among Families of Childhood Brain Tumours in Australia

Pediatric Blood &Cancer, EarlyView.
ABSTRACT Background Families of children with cancer experience significant financial strain, even with universal healthcare. Indirect costs, such as productivity losses and non‐medical expenses, are rarely included in economic evaluations, and little is known about how effectively financial aid programmes alleviate this burden. Childhood brain tumours
Megumi Lim, Natalie Bradford, David Brain, Sameera Senanayake, Sanjeewa Kularatna, Kate Young, Christine Cashion, Tim Hassall, Susanna Cramb   +8 more
wiley   +1 more source

Symmetry group analysis of an ideal plastic flow

, 2011
In this paper, we study the Lie point symmetry group of a system describing an ideal plastic plane flow in two dimensions in order to find analytical solutions. The infinitesimal generators that span the Lie algebra for this system are obtained.
Chakrabarty J., Czyz J., Hill R., Janenko N. N., Katchanov L., Ovsiannikov L. V., Vincent Lamothe   +6 more
core   +1 more source