Recent content by agostino981

Just saying, I thought the blob was Green function. I guess this is probably the matter of convention. Can we simply use a single Green function to represent the whole electron-proton interaction instead?

Electromagnetic (mediated by photons), strong (mediated by gluons) and weak (mediated by W and Z bosons) interactions are mediated by virtual particles. Graviton is also a hypothetical boson that mediates gravity.

I am not an expert in the field, but if you look for a really brief explanation, this is what graviton is: 1. a massless and stable particle, so it has infinite range, just like photon 2. a particle that mediates gravitation 3. a spin 2 particle, as it can be shown that a spin 2 particle...

Thanks! That clears things up.

I am a bit confused here. In the Einstein Field Equation, there is a tensor called stress-energy tensor in wikipedia and energy-momentum tensor in some books or papers which is $$T_{\mu\nu}=\frac{2}{\sqrt{-g}}\frac{\delta(\mathcal{L} \sqrt{-g})}{\delta g_{\mu\nu}}$$ Is it equivalent to the...

I am a bit confused. Isn't it the "definition" of differentiable manifold instead of manifold?

I would suggest you to use energy instead.