Fractional Calculus & Inverse Laplace Transforms
- To: mathgroup at smc.vnet.net
- Subject: [mg35138] Fractional Calculus & Inverse Laplace Transforms
- From: jonathan.landy at roche.com (Jonathan)
- Date: Tue, 25 Jun 2002 19:55:23 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hi, I've been working on an inverse Laplace transform, here it is: (1) w 1 L-1 [ --------- * ----- ] , -1<a<1, a!=0 S^2 + w^2 s^a I solved this by extending the following identity to fractional powers of a: L^-1 [ f(s)/s^a ] = (I^a o f)(t) = a indefinite integrals of f(t); Now,for my solution I got an infinite series, this is alright because the other method of solving the problem gave some hypergeometric solutions that were more complicated. I plugged my solution into mathematica and took the Laplace trasform and it gave (1)! However if one gives a value for a, I get a hypergeometric equation again. So my questions are: is mathematica assuming that a is an integer the first time I ran the thing? Also does anyone know if I can even make the assumption that I did (that the identity for the inverse laplace works for fractional a)? It appears that I can, because I tested it on some cases one can do by hand, but that is by no means a proof that it works in general. However, most of the stuff in fractional calculus is just a definition anyways, so maybe this is ok? I don't know. Thanks for the help. Also, please can you respond through the message board, because my email account is not working very well right now. thanks again.