Recent content by cohen990

Okay so in a HDM scenario, I have seen it described that the neutrinos were relativistic at freeze out. (If I could find it I would reference it.) Is this a contradictory statement? The condition for relativistic travel is E>>m but just before freezeout, the neutrino has energy equal to...

I am an undergrad physicist and I wrote a mini-dissertation on hydrogen power. My professor told me I should consider getting it published in a science magazine like scientific american or physics world or something. How would I go about this? Do I just send it in and hope for the best...

Thanks for your help. It makes more sense now. Supersymmetric dark matter If you have access, it's worth a look ^_^ Thanks again

Well the phrase he uses is referring to <\sigma_{A}v>, the annihilation cross section.

Ah, thanks. Silly mistake :< Any thoughts on my second question?

Hi, I'm reading an article called SuperSymmetric Dark Matter, by G. Jungman et al. doi:10.1016/0370-1573(95)00058-5 and in section 3.2, he claims that <σv> ≈ \alpha^{2}(100 GeV)^{-2} \approx10^{-25} cm^{3} s^{-1},[\itex] for \alpha \approx \frac{1}{100}. When I run through the calculation...

I'm reading a paper on photovoltaic hydrogen production and the author claims that for reasonable solar efficiencies the band gap must be less than 2.0eV. This I understand. My question is how will it effect the photon absorption if the band gap is much smaller. Say the band gap energy is...