Recent content by gasgas

I see, so a more precise way to say this is that m(##\partial\mu, \partial\nu##)=m(##\partial\nu, \partial\mu##) where m is multiplication in U(g), while this does not apply to an element of U(g)##\otimes##U(g). Thank you!

I will just link the source I'm using if that's fine. All the definitions are in the first chapter of this PhD thesis https://arxiv.org/pdf/1210.1115

I am studying the mathematical formalism behind non-commutative geometry approach to quantum gravity. I was reading about Hopf algebras and their Drinfeld twist with a specific example of the Moyal-Weyl twist defined as F=exp(-iλ/2θ^(μν)∂_μ⊗∂_ν) where λ is a constant parametar and θ...

I'm currently going through Peskin and Schroeder's Intro to QFT textbook, chapter 4.2 "Perturbation Expansion of Correlation Functions". So we use the evolution of an operator in the Heisenberg picture from some time t0 to an arbitrary time t>t0 assuming we know how the field looks at t0. Then...

Thank you so much, I will study these notes further.

Hello, I'm having quite a lot of trouble with working through the proof of this proposition in Hawking and Ellis's "Large Scale Structure of Spacetime". First of all, I am unsure of how the matrix element A that is in the proof can be the same matrix element as in equation 4.39 because there we...

If we consider the coefficient b as the rings impedance, we can consider the effective impedance on the right to be b+Z2 where Z2 is the impedance of the second string. Then because there is no reflection it follows that Z1=b+Z2 or b=Z1-Z2. Is this a valid solution? My professor went through a...