Recent content by Anne-Sylvie

Maybe I wasn't clear enough with my question. I am wondering why are they so few polarized photons. :)

Hello everyone, I am a student in particle physics and cosmology in some Belgian university. I'll finish my master degree in June of this year. I am searching for PhD studentships in Europa or US, but it is very difficult to get a place somewhere. I applied to some universities, I'm still...

Hello everyone :) The CMB is polarized. I read in Dodelson's book "Modern Cosmology" that we can expect a signal of polarization weaker than the signal of temperature. Is it only because the Stokes parameters obey $$I^2 = Q^2 + U^2 $$ (I drop V because Thomson scatering can't create V...

Hello everybody, (sorry for the eventual Engrish) I can't find any convincing answer for the following question : Why do we always (or often) plot the CMB power spectrum in this way : jb.man.ac.uk/research/cosmos/vsa/images/CMB_power_spectrum.gif I mean the y-axis is $$C_\ell \ell...

Thanks very much for your answer. In fact, the matrix that I give is unitary as you said. But this is not EXACTLY the matrix as in the paper of Kobayashi and Maskawa ; The V_3,3 term have been corrected. In the paper they write a sin(θ3) term in place of a cos(θ3) term. Thank you ! :smile:

Hello everyone, I'm studying some lectures on electroweak interactions and I was reading the paper from Kobayashi and Maskawa, particulary the matrix : But these matrix have to be unitary... And my professor said that it was not the case. When I compute the product of this matrix and...

Thanks for your advice. :-)

Hello everyone, When we speak about the SU(2)L group (in electroweak interactions for example), about what group do we talk ? What is the difference with the SU(2) group ? And with the SU(2)R ? Why is the label so important ? I ask this because I see that a Lagrangien can be invariant...

Indeed. Thanks !

Hello QuArK, Thanks for your answer. The pdf link is interesting. But I'm searching a more physical and intuitive answer... Why a higher opacity implies a lower effective temperature ? Edit : I think I have got it ! http://www2.astro.psu.edu/users/rbc/a534/lec18.pdf On the third page. Thanks...

Hey everyone, This is my first post on this forum. Please tell me if I do some mistake. :) So, there is my question ; I have search a long time on the web but I don't find any answer... Why the metallicity influences the effective temperature and the luminosity of a star ? I read...