Results 31 to 40 of about 7,793,267 (329)

Group-Invariant Solutions of Differential Equations [PDF]

SIAM Journal on Applied Mathematics, 1987
The authors describe a general approach to group-invariant solutions of partial differential equations. They introduce the concept of a ''weak symmetry group'' of a system of partial differential equations and show how, in principle, to construct group-invariant solutions for any group of transformations by reducing the number of variables in the ...
Olver, Peter J., Rosenau, Philip
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Solutions of gauge invariant cosmological perturbations in long-wavelength limit [PDF]

, 1998
We investigate gauge invariant cosmological perturbations in a spatially flat Friedman-Robertson-Walker universe with scalar fields. It is well known that the evolution equation for the gauge invariant quantities has exact solutions in the long ...
Atsushi Taruya, Garcia-Bellido J, Hwang J, Kodama H, Langlois D, Mukhanov V F, Mukhanov V F, Sasaki M, Taruya A, Yasusada Nambu   +9 more
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Kaluza-Klein and H-Dyons in String Theory [PDF]

, 1998
Kaluza-Klein monopole and H-monopole solutions, which are T-dual to each other, are the well-known solutions of string theory compactified on $T^6$. Since string theory in this case has an S-duality symmetry, we explicitly construct the corresponding ...
A. Das, A. Font, A. Giveon, A. Hanany, A. Sen, A. Sen, A. Sen, A. Shapere, C. Hull, C. Hull, D. Gross, D. Zwanziger, D. Zwanziger, E. Alvarez, E. Bergshoeff, E. Cremmer, E. Eyras, E. Witten, G. Gibbons, G. Horowitz, J. Blum, J. Gauntlett, J. Maharana, J. Schwarz, J. Schwarz, J. Schwarz, J. Schwarz, J. Schwinger, J. Schwinger, J. X. Lu, M. Cvetic, M. Cvetic, M. Cvetic, M. de Roo, M. Duff, P. Dirac, P. Ruback, R. Gregory, R. Khuri, R. Khuri, R. Khuri, R. Sorkin, S. J. Rey, S. Roy, Shibaji Roy, T. Banks, Y. Imamura   +46 more
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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
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GROUP-INVARIANT SOLUTIONS, NON-GROUP-INVARIANT SOLUTIONS AND CONSERVATION LAWS OF QIAO EQUATION

Journal of Applied Analysis & Computation, 2019
Summary: This paper considers a completely integrable nonlinear wave equation which is called Qiao equation. The equation is reduced via Lie symmetry analysis. Two classes of new exact group-invariant solutions are obtained by solving the reduced equations.
Shi, Jianping, Zhou, Mengmeng, Fang, Hui
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Optimizing option pricing: Exact and approximate solutions for the time-fractional Ivancevic model

Alexandria Engineering Journal, 2023
This research investigates the time fractional Ivancevic option pricing model and presents two distinct solution methods: the invariant subspace method for obtaining exact solutions and the residual power series method for generating approximate ...
Khalid K. Ali, M.A. Maaty, M. Maneea
doaj   +1 more source

Scale-invariance in expanding and contracting universes from two-field models [PDF]

, 2007
We study cosmological perturbations produced by the most general two-derivative actions involving two scalar fields, coupled to Einstein gravity, with an arbitrary field space metric, that admit scaling solutions.
Andrew J Tolley, Bozza V, Bozza V, Brandenberger R, Buchbinder E I Khoury J Ovrut B A, Creminelli P Senatore L, Daniel H Wesley, Groot Nibbelink S, Hwang J c, Karthauser J L P, Kodama H, Koyama K Wands D, Lehners J L McFadden P Turok N Steinhardt P J, McFadden P L Turok N Steinhardt P J, Nambu Y, Starobinsky A A, Starobinsky A A, Starobinsky A A Yokoyama J, van Tent B J W   +18 more
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Studying a Tumor Growth Partial Differential Equation via the Black–Scholes Equation

Computation, 2020
Two equations are considered in this paper—the Black–Scholes equation and an equation that models the spatial dynamics of a brain tumor under some treatment regime. We shall call the latter equation the tumor equation.
Winter Sinkala, Tembinkosi F. Nkalashe
doaj   +1 more source

Quantum critical lines in holographic phases with (un)broken symmetry [PDF]

, 2013
All possible scaling IR asymptotics in homogeneous, translation invariant holographic phases preserving or breaking a U(1) symmetry in the IR are classified. Scale invariant geometries where the scalar extremizes its effective potential are distinguished
A Adam, A Adams, A Donos, A Donos, A Donos, A Salvio, A Zamolodchikov, B Goutéraux, B Goutéraux, B. Goutéraux, BS Kim, BS Kim, C Charmousis, C Charmousis, C Charmousis, D Arean, D Cassani, DT Son, E Kiritsis, E Perlmutter, E Shaghoulian, E. Kiritsis, F Aprile, GT Horowitz, GT Horowitz, GW Gibbons, I Iatrakis, I Iatrakis, I Kanitscheider, J Bhattacharya, JM Maldacena, JP Gauntlett, JP Gauntlett, K Balasubramanian, K Goldstein, K Goldstein, L Huijse, M Edalati, M Jarvinen, M Lassig, N Iizuka, N Iizuka, N Iqbal, N Ogawa, R Casero, RJ Anantua, S Franco, S Kachru, S Nakamura, SA Hartnoll, SA Hartnoll, SA Hartnoll, SA Hartnoll, SA Hartnoll, SS Gubser, SS Gubser, SS Gubser, SS Gubser, SS Gubser, T Alho, T Faulkner, T Faulkner, U Gürsoy, U Gürsoy, U Gürsoy, U Gürsoy, W Chemissany, W Chemissany, X Dong, Y Liu   +69 more
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Symmetry analysis and invariant solutions of generalized coupled Zakharov-Kuznetsov equations using optimal system of Lie subalgebra

International Journal of Mathematics and Computer in Engineering
This research focuses on the examination of nonlinear evolution equations, with a specific emphasis on the generalized coupled Zakharov-Kuznetsov (CZK) equations serving as a primary application.
M. Usman, A. Hussain, F. Zaman, Naseem Abbas   +3 more
semanticscholar   +1 more source