Recent content by quangtu123

As the way I see all general relativity and non-gravitation quantum physics can be constructed from the groups of symmetry (in broad sense). It's somewhat really awesome. Is there any idea like this to pursue a quantum gravity theory?

http://physics.stackexchange.com/questions/46324/to-which-extent-is-general-relativity-a-gauge-theory It seems like there is some mathematical similarities between gauge theory and GR.

First I want to consider an example of 1D motion. Lagrange equation: $$ \frac{d}{dt} \frac{\partial L}{\partial \dot x} - \frac{\partial L}{\partial x} = 0 $$ If we transform $$L \rightarrow L+a$$ with a is constant, the equation of motion remains unchanged. This is global symmetry. To obtain...

It seems to me like in the representation theory of particle physics, the groups chosen (to form representation) are groups of symmetry operators. It starts to make sense. Like the representation theory is the next step of symmetry in physics. Am I wrong?

I'm starting to learn about particle physics but I really want to see the whole picture before going deep. Here is what I know: - There are symmetries in quantum physics, which are symmetry operators commute with the Hamiltonian (translation operators, rotation operators...) which act on a...

I haven't thought that we will come back to Riemann integral to define the integral of a k_form. It starts to make sense now. Thanks you guys!

Ok so what would happen if I put a fluid inside some other fluid?

To what I know, surface tension is a force that appear at the interface between 2 bulk phases, and is parallel to that interface. Let consider a bulk of a fluid in the air. In the bulk of a fluid at rest, two sub-parts of a fluid exert a attractive force on one another due to surface tension...

It seems like there are many ways to imagine a differential form. I have a feeling that a k_form is simply something have the form of (a,b,...,k) that is linear-in-each-argument and alternating. A sum, an operator,... How can we integrate a somewhat mysterical object like that? (I want to...

Thank you so much! Before when I read science-popular books I thought in GR we will deal with accelerated frames (by instantaneous inertial frames and SR, as explaining the twin paradox); put it into equivalence principle and then we have a theory of gravitation. Now I think gravitation and...

I have read some basics knowledge about General Relativity and I see that it deal perfectly with gravity. But what about accelerated frames? Is there something similar to Lorentz Transformation for accelerated frame in General Relativity? (so that i can solve, maybe, the general twin paradox)...

Ok it's an alternative, but what is it? I mean, how can I imagine a differential form in my head?

I'm reading about multlinear algebra and I'm stuck at differential form and outer product. The definitions involve tensor product and quotient set and I really cannot grab the concrete idea of the differential form. Can someone explain in a somewhat layman term what is differential form...