Re: Apparent error integrating product of DiracDelta's

*To*: mathgroup at smc.vnet.net*Subject*: [mg91962] Re: Apparent error integrating product of DiracDelta's*From*: "Nasser Abbasi" <nma at 12000.org>*Date*: Mon, 15 Sep 2008 03:40:55 -0400 (EDT)*References*: <gag2lg$39k$1@smc.vnet.net>*Reply-to*: "Nasser Abbasi" <nma at 12000.org>

"Michael Mandelberg" <mmandelberg at comcast.net> wrote in message news:gag2lg$39k$1 at smc.vnet.net... > How do I get: > > Integrate[DiracDelta[z- x] DiracDelta[z- y], {z-Infinity, Infinity}] > > to give DiracDelta[x-y] as the result? Currently it gives 0. I have > all three variable assumed to be Reals. I am using 6.0.0. > > Thanks, > Michael Mandelberg > I think you have synatx error in the limit part. I assume you mean to write {z, -Infinity,Infinity} Given that, I think zero is the correct answer. When you multiply 2 deltas at different positions, you get zero. Integral of zero is zero. Nasser