Abstract
Differential-difference equations (DDEs) u(k)n (t) = Fn(t,Un+a,...,Un+b) for k ≥ 2 are studied for their differential Lie symmetries. We observe that while nonintrinsic Lie symmetries do exist in such DDEs, a great many admit only the intrinsic ones. We also propose a mechanism for automating symmetry calculations for fairly general DDEs, with a variety of features exemplified. In particular, the Fermi-Pasta-Ulam system is studied in detail and its new similarity solutions given explicitly.
| Original language | English |
|---|---|
| Pages (from-to) | 137-143 |
| Number of pages | 7 |
| Journal | Physics Letters. Section A: General, Atomic and Solid State Physics |
| Volume | 240 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 30 Mar 1998 |
| Externally published | Yes |
Keywords
- Differential-difference equations
- Integrability
- Lie point symmetries