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seen Aug 18 '11 at 0:17

Aug
14
comment Can the following be integrated?
@mixedmath thanks. I can't seem to do it numerically because when integrating the whole thing (including extra functions of y and z) over x, y and z, mathematica can't figure out where the singularities are.
Aug
14
comment Can the following be integrated?
I don't, but sometimes an integral that looks more complicated is actually simpler, and I wanted to make sure I wasn't missing something like that.
Aug
14
awarded  Supporter
Apr
27
accepted Can you differentiate with respect to a sum?
Apr
27
awarded  Commentator
Apr
27
comment Can you differentiate with respect to a sum?
And I'll think some more about the ordering - thank you.
Apr
27
comment Can you differentiate with respect to a sum?
@joriki Ahh so it should be $(\delta /\delta x(\tau')) Exp[\int_0^p d\tau (x(\tau) \alpha (\tau) - y(\tau) \beta (\tau))] = \alpha (\tau') Exp[\int_0^p d\tau (x(\tau) \alpha (\tau) - y(\tau) \beta (\tau))]$ ? (But possibly with the $\alpha$ after the integral rather than before).
Apr
27
comment Can you differentiate with respect to a sum?
@joriki since $x$ is in front of $\alpha$, I don't think it should matter that they're Grassmann numbers.. Should it?
Apr
27
comment Can you differentiate with respect to a sum?
@joriki I used to write the same $\tau$ for all, but have been told the way I wrote it above is the correct way since when they are all tau, it looks like you're differentiating wrt the integration variable.
Apr
27
comment Can you differentiate with respect to a sum?
And sorry, i'm not sure why I said operators! Must be a lack of sleep. I meant Grassmann numbers!
Apr
27
comment Can you differentiate with respect to a sum?
@joriki I'm not sure what you mean by that there's no need for the Integrating variables to be different...
Apr
27
revised Can you differentiate with respect to a sum?
added 370 characters in body
Apr
27
comment Can you differentiate with respect to a sum?
@joriki thanks. I tried to simplify the problem to much I think. I've edited my question again to hopefully make it clearer.
Apr
26
comment Can you differentiate with respect to a sum?
$a$, $b$, $\alpha$ and $\beta$ are also operators rather than just variables. Does this make any difference?
Apr
26
comment Can you differentiate with respect to a sum?
@joriki thanks. So since what I want is to find $\alpha Exp[(5a+3b)\alpha−(3a+5b)\beta]$ (or $\alpha Exp[x\alpha−y\beta]$ is fine too), the useful meaning for me of $\partial / \partial x$ is $\partial / \partial (5a+3b)$?
Apr
26
revised Can you differentiate with respect to a sum?
added 39 characters in body
Apr
26
revised Can you differentiate with respect to a sum?
added 88 characters in body
Apr
26
awarded  Scholar
Apr
26
awarded  Student
Apr
26
accepted Can a product of 2 step functions be integrated?