Hi all,(adsbygoogle = window.adsbygoogle || []).push({});

I'm working on a Green function chapter of my dissertation, am referencing the equation,

[tex]G(k,\omega) = \int_{-\infty}^\infty \frac{A(k,\omega')d\omega'}{\omega - \omega' + i0^+},[/tex]

and I am trying to figure out the best way to credit it. I have noticed that condensed matter texts (Schrieffer, Mahan, for example) call it the "Lehmann" spectral representation, but Peskin and Schroeder and Wikipedia call it the "Kallen-Lehmann" spectral representation. Is there any reason I should not be also crediting Kallen for the formula above? The Peskin and Schroeder version of the equation (see p. 215) is slightly different from what I wrote above, but most of the differences seem like convention issues to me.

Thanks!

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# Who is this "Kallen" and what does he represent, anyway?

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