petrushka.googol Posted February 6, 2015 Posted February 6, 2015 Does dark energy obey Einsteins mass-energy equation E = mc2,, I was just curious to know ? If it does then how ? Thanks in advance.
Mordred Posted February 6, 2015 Posted February 6, 2015 (edited) Well we don't know what causes the cosmological constant, so the m term is simply an energy Mass equivalent. However the Einstein field equations relate to the cosmological constant aka dark energy(one possible contributor) via the stress energy tensor. [latex]T_{\mu\nu}=\frac{\Lambda c^4}{8\pi G}G_{\mu\nu}[/latex] http://en.m.wikipedia.org/wiki/Einstein_field_equations http://en.m.wikipedia.org/wiki/Stress%E2%80%93energy_tensor take a good look at the stress energy tensor matrix on the second link This correlates the energy density to pressure relations of the cosmological constant. In the FLRW metric it is determined by its equation of state http://en.m.wikipedia.org/wiki/Equation_of_state_(cosmology) [latex]w=\frac{\rho}{p}[/latex] For the cosmological constant w= -1 This article provides some further detail http://cosmology101.wikidot.com/universe-geometry Page 2 FLRW distance measures http://cosmology101.wikidot.com/geometry-flrw-metric/ In short we can relate its energy density to pressure influence. As energy and mass has an equivalence we can also calculate its estimated mass density via the critical density formula. http://en.m.wikipedia.org/wiki/Critical_density_(cosmology)#Density_parameter The calculations give 1.89*10-27 grams/cm^3 Edited February 6, 2015 by Mordred 2
xyzt Posted February 6, 2015 Posted February 6, 2015 (edited) Does dark energy obey Einsteins mass-energy equation E = mc2,, I was just curious to know ? If it does then how ? Thanks in advance. The correct formulation is either: 1. The total energy E contained by a proper mass [math]m_0[/math] is [math]E=\gamma m_0c^2[/math] 2. The variation of total energy [math]\Delta E[/math] released by a variation of proper mass [math]\Delta m_0[/math] is [math]\Delta E=c^2 \Delta m_0[/math] 3. In the rest frame co-moving with the mass [math]m_0[/math] the total energy is equal to the rest energy [math]E_0=m_0c^2[/math] because [math]\gamma=1[/math] [math]E=mc^2[/math] is a (bad) shorthand for either 1,2 or 3. Now, there is no mass associated with dark energy, so your question cannot be answered. Edited February 6, 2015 by xyzt
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now