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Unformatted text preview: Phys 7268 Midterm exam Due: 3/10/11 Problem 1 Generalizations of Swift-Hohenberg equation. The form of the Swift-Hohenberg equation is determined by the symmetries of the system, such as translational and rotational symmetries. For instance, breaking the parity symmetry leads to an extra term s x u with s an arbitrary constant: t u = ru + s x u- (1 + 2 x ) 2 u- u 3 . (a) Compute the growth rate and determine the type of instability (i.e., I s , III o , etc.) of the trivial solution u = 0 which arises for different values of parameter s . Furthermore, determine the coherence length c , the characteristic timescale and, if the instability is oscillatory, the characteristic frequency c . (b) By substituting the growth rate into the linear solution determine the meaning of the new term. Can you show that by a suitable change of variables the above equation can be reduced to a standard Swift-Hohenberg equation?...
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This note was uploaded on 08/25/2011 for the course PHYS 7268 taught by Professor Staff during the Spring '11 term at Georgia Institute of Technology.
- Spring '11