DiracDelta Integrals
- To: mathgroup at smc.vnet.net
- Subject: [mg9185] DiracDelta Integrals
- From: Peter Jay Salzman <psalzman at landau.ucdavis.edu>
- Date: Tue, 21 Oct 1997 02:02:58 -0400
- Sender: owner-wri-mathgroup at wolfram.com
dear mathgroup,
just out of curiosity, i tried
Integrate[ Exp[I k x], {x, -Infinity, Infinity}]
and Mathematica said "the integral is 0 if Im[k]==0, otherwise, i give
up". so, thinking i was being slick, i loaded the
Calculus`DiracDelta` package.
i tried the integral again, but Mathematica said the same thing. then,
knowing that this comes up all the time in fourier transforms, i loaded
Calculus`FourierTransform`. this time, when i entered the integral,
Mathematica told me: "hey, bubba. that integral doesn't converge on
the domain of integration".
surely, there MUST be a package that allows Mathematica to do this
integral and give me 2 Pi DiracDelta[k]. what do i need to load to
make Mathematica recognize this?
the reason why i'm asking is because i'm trying to do the integral
Exp[-Abs[k]/c] Exp[I k x] Exp[i p x/hbar], {x,-Infinity,Infinity},
{k, -Infinity, Infinity}
by the way, are there any packages that allow bra-ket notation on
Mathematica? i would find it hard to believe that Mathematica has the
RiemannSiegelTheta function but couldn't compute something like <f|f>.
peter
--
Never criticize a man till you've walked a mile in his shoes. That way,
you'll be a mile away from him and have his shoes as well.
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