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An analytical and numerical study of the two-dimensional Bratu equation

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dc.contributor Department of Atmospheric and Oceanic Science and Laboratory for Advanced Scientific Computation, University of Michigan, 48109, Ann Arbor, Michigan
dc.contributor Ann Arbor
dc.creator Boyd, John P.
dc.date 2006-09-11T15:31:10Z
dc.date 2006-09-11T15:31:10Z
dc.date 1986-09
dc.date.accessioned 2022-05-19T13:30:03Z
dc.date.available 2022-05-19T13:30:03Z
dc.identifier Boyd, John P.; (1986). "An analytical and numerical study of the two-dimensional Bratu equation." Journal of Scientific Computing 1(2): 183-206. <http://hdl.handle.net/2027.42/44977>
dc.identifier 0885-7474
dc.identifier 1573-7691
dc.identifier http://hdl.handle.net/2027.42/44977
dc.identifier http://dx.doi.org/10.1007/BF01061392
dc.identifier Journal of Scientific Computing
dc.identifier.uri http://localhost:8080/xmlui/handle/CUHPOERS/117317
dc.description Bratu's problem, which is the nonlinear eigenvalue equation Δu+λ exp( u )=0 with u =0 on the walls of the unit square and λ as the eigenvalue, is used to develop several themes on applications of Chebyshev pseudospectral methods. The first is the importance of symmetry : because of invariance under the C 4 rotation group and parity in both x and y , one can slash the size of the basis set by a factor of eight and reduce the CPU time by three orders of magnitude. Second, the pseudospectral method is an analytical as well as a numerical tool: the simple approximation λ ≈3.2A exp(−0.64 A ), where A is the maximum value of u(x, y) , is derived via collocation with but a single interpolation point, but is quantitatively accurate for small and moderate A . Third, the Newton-Kantorovich/Chebyshev pseudospectral algorithm is so efficient that it is possible to compute good numerical solutions—five decimal places—on a microcomputer in basic . Fourth, asymptotic estimates of the Chebyshev coefficients can be very misleading: the coefficients for moderately or strongly nonlinear solutions to Bratu's equations fall off exponentially rather than algebraically with v until v is so large that one has already obtained several decimal places of accuracy. The corner singularities, which dominate the behavior of the Chebyshev coefficients in the limit v →∞, are so weak as to be irrelevant, and replacing Bratu's problem by a more complicated and realistic equation would merely exaggerate the unimportance of the corner branch points even more.
dc.description Peer Reviewed
dc.description http://deepblue.lib.umich.edu/bitstream/2027.42/44977/1/10915_2005_Article_BF01061392.pdf
dc.format 1086454 bytes
dc.format 3115 bytes
dc.format application/pdf
dc.format text/plain
dc.format application/pdf
dc.language en_US
dc.publisher Kluwer Academic Publishers-Plenum Publishers; Plenum Publishing Corporation ; Springer Science+Business Media
dc.subject Bratu's Problem
dc.subject Computational Mathematics and Numerical Analysis
dc.subject Mathematical and Computational Physics
dc.subject Mathematics
dc.subject Algorithms
dc.subject Appl.Mathematics/Computational Methods of Engineering
dc.subject Nonlinear Eigenvalue Problem
dc.subject Spectral Methods
dc.subject Science (General)
dc.subject Education
dc.subject Science
dc.subject Social Sciences
dc.title An analytical and numerical study of the two-dimensional Bratu equation
dc.type Article


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