Constants¶
- colibri.constants.explanatory()[source]¶
This file contains a series of physical constants and conversion factors which are used in the other codes. Also useful quantities not strictly related to cosmology are defined.
Conversion factors, distance
km_to_cm
: 1 km in cmkm_to_m
: 1 km in mpc_to_cm
: 1 pc in cmpc_to_m
: 1 pc in mpc_to_km
: 1 pc in kmkpc_to_cm
: 1 kpc in cmkpc_to_m
: 1 kpc in mkpc_to_km
: 1 kpc in kmMpc_to_cm
: 1 Mpc in cmMpc_to_m
: 1 Mpc in mMpc_to_km
: 1 Mpc in km
Conversion factors, time
yr_to_s
: 1 yr in sMyr_to_s
: 1 Myr in s
Conversion factors, energy
eV
: electron-Volt in \(\mathrm{J}\)keV
: kilo Electron-Volt in \(\mathrm{J}\)MeV
: mega Electron-Volt in \(\mathrm{J}\)GeV
: giga Electron-Volt in \(\mathrm{J}\)TeV
: tera Electron-Volt in \(\mathrm{J}\)
Proton & electron mass & charges
mp
: proton mass in \(\mathrm{eV}\)mp_g
: proton mass in \(\mathrm{g}\)mp_J
: proton mass in \(\mathrm{J}\)me
: eletron mass in \(\mathrm{eV^2}\)me_g
: eletron mass in \(\mathrm{g}\)me_J
: eletron mass in \(\mathrm{J}\)q
: electron/proton charge in \(\mathrm{C}\)
Neutrino properties
Delta_m21_squared
: difference of squared masses in \(\mathrm{eV^2}\)Delta_m32_squared_IH
: difference of squared masses in \(\mathrm{eV^2}\)Delta_m32_squared_NH
: difference of squared masses in \(\mathrm{eV^2}\)sin_theta_21_squared
: sine squared of mixing anglesin_theta_23_squared_IH
: sine squared of mixing angle, inverted hierarchysin_theta_23_squared_NH
: sine squared of mixing angle, normal hierarchysin_theta_13_squared
: sine squared of mixing angle
Constants of physics
G
: Newton’s gravitational constant in units of \(\mathrm{Mpc} \ M_\odot (\mathrm{km/s})^2\)eps_0
: vacuum permittivity in \(\mathrm{F/m = C/V \ m}\)mu_0
: magnetic permeability in \(\mathrm{H/m = T \ m^2/A = V \ s/A}\)kB
: Boltzmann constant in \(\mathrm{eV/K}\)c
: speed of light in \(\mathrm{km/s}\)hP
: Planck constant in units of \(\mathrm{eV \ s}\)sSB
: Stefan-Boltzmann constant in \(\mathrm{W \ m^{-2} \ K^{-4}}\)N_A
: Avogadro constant in \(\mathrm{mol^{-1}}\)
Derived constants
e2
: electron/proton charge (squared!) in CGS unitshPb
: reduced Planck constant (\(\bar{h}\)) in \(\mathrm{eV \ s}\)hPJ
: Planck constant in \(\mathrm{J \ s}\)hPJb
: reduced Planck constant (\(\bar{h}\)) in \(\mathrm{J \ s}\)sSB_eV
: Stefan-Boltzmann constant in \(\mathrm{eV \ m^{-2} \ K^{-4}}\)alpha_BB
: constant for blackbody energy density in \(\mathrm{J \ m^{-3} \ K^{-4}}\)R
: perfect gas constant in \(\mathrm{J \ mol^{-1} \ K^{-1}}\)alpha_EM
: fine structure constantlambda_e
: Compton wavelength for electron in \(\mathrm{m}\)r_e
: electron classical radius in \(\mathrm{m}\)sigma_T
: Thomson scattering cross section in \(\mathrm{m}^2\)rhoch2
: critical density of the Universe \(h^2 \ M_\odot \ \mathrm{Mpc}^{-3}\)
Planck units
l_Pl
: Planck length in \(\mathrm{m}\)t_Pl
: Planck time in \(\mathrm{s}\)m_Pl
: Planck mass in \(\mathrm{g}\)T_Pl
: Planck temperatur in \(\mathrm{K}\)q_Pl
: Planck charge in \(\mathrm{C}\)
Solar units
Msun
: solar mass in \(\mathrm{g}\)Rsun
: solar radius in \(\mathrm{cm}\)Tsun
: solar surface temperature in \(\mathrm{K}\)Lsun
: solar luminosity in \(\mathrm{erg \ s^{-1}}\)