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comment Origin of cusps in simulated dark matter halos
Yes, via their gravitational attraction.
Aug
26
comment Origin of cusps in simulated dark matter halos
The most popular explanation is that there is no cusp due to the presence of baryons which need hydrodynamic simulations to be accurately described.
Aug
14
comment Relativistic Energy
There is a nice Wikipedia article on mass in general relatvity:en.wikipedia.org/wiki/Mass_in_general_relativity . What John has described is known as the Newtonian limit for the mass.
Aug
4
comment Density of dark matter along the galaxy
There is a small inaccuracy in your post, close to the center of the galaxy the NFW gives $\rho\propto r^{-1}$ not $\rho\propto r^{-2}$.
Jul
29
awarded  Civic Duty
Jul
27
comment Why does humidity cause a feeling of hotness?
OK, he is saying tempratures between 30°C and 36°C at high humidity are worse than temperatures greater than 37°C at low humidity. Not sure why it wasn't clear to me at first.
Jul
27
comment Why does humidity cause a feeling of hotness?
Is there a typo in the last sentence?
Jul
15
comment Mass density of dark matter in solar system near us
Or in other words, roughly 400 thousand protons' mass of dark matter per cubic meter or about half a proton's mass per cubic centemeter.
Jul
15
comment Mass density of dark matter in solar system near us
With error bars (adding uncertainties in quadrature) it is $(0.4\pm 0.1)$GeV/cm$^3$.
Jul
11
comment Transition from one state to another in Quantum Mechanics
Nice answer, but I would leave out "Single particle theories don't really work for reasons discussed in lots of books on quantum field theory. A very clear discussion is given in "Quantum Field Theory for the Gifted Amateur" by Lancaster and Blundell Chapter 8." Also I think the "Me" in your evolution operator equation should just be "e".
Jul
6
comment Is the Legendre transformation a unique choice in analytical mechanics?
I wonder if there is a typo in the following sentence: "... does not happen for field theories and interacting particles theories (it does happen for the point particle, though)". Its seems a bit unclear as obviously point particles can also be interacting.
Jun
29
answered Single field vs single clock inflation?
Jun
29
answered Possible values of an observable are the eigenvalues of an operator
Jun
18
awarded  Yearling
Jun
7
comment How many particles in $\phi_0(x)^2|0\rangle$?
One more question: shouldn't $$N{\phi^+}^2(x)|0\rangle = 2 {\phi^+}^2(x)|0\rangle$$ be $$N{\phi^-}^2(x)|0\rangle = 2 {\phi^-}^2(x)|0\rangle$$ ?
Jun
7
accepted How many particles in $\phi_0(x)^2|0\rangle$?
Jun
7
comment How many particles in $\phi_0(x)^2|0\rangle$?
Thanks again for your help.
Jun
7
comment How many particles in $\phi_0(x)^2|0\rangle$?
Thanks, that's very helpful. Should the + and - be swapped around in that last line?
Jun
7
asked How many particles in $\phi_0(x)^2|0\rangle$?
Jun
6
accepted Order of index in Lorentz transform