Functions | Variables
o2scl_const Namespace Reference

Constants. More...

Functions

template<class fp_t >
fp_t planck_f (size_t system=o2scl_mks)
 Planck constant.
 
template<class fp_t >
fp_t hbar_f (size_t system=o2scl_mks)
 Reduced Planck constant.
 
template<class fp_t >
fp_t speed_of_light_f (size_t system=o2scl_mks)
 Speed of light.
 
template<class fp_t >
fp_t elem_charge_f ()
 Elementary charge.
 
template<class fp_t >
fp_t hc_mev_fm_f ()
 Reduced Planck constant times speed of light in $ \mathrm{MeV}~\mathrm{fm} $.
 

Variables

const double yotta =1e24
 
const double zetta =1e21
 
const double exa =1e18
 
const double peta =1e15
 
const double tera =1e12
 
const double giga =1e9
 
const double mega =1e6
 
const double kilo =1e3
 
const double milli =1e-3
 
const double micro =1e-6
 
const double nano =1e-9
 
const double pico =1e-12
 
const double femto =1e-15
 
const double atto =1e-18
 
const double zepto =1e-21
 
const double yocto =1e-24
 
const double fine_structure =7.2973525693e-3
 Fine structure constant (CODATA 2018 value)
 
const double avogadro =6.02214076e23
 Avogadro's number (CODATA 2018 value; exact)
 
const double pi =boost::math::constants::pi<double>()
 $ \pi $
 
const double pi2 =boost::math::constants::pi_sqr<double>()
 $ \pi^2 $
 
const double zeta32 =2.6123753486854883433
 $ \zeta(3/2) $
 
const double zeta2 =boost::math::constants::zeta_two<double>()
 $ \zeta(2) $
 
const double zeta52 =1.3414872572509171798
 $ \zeta(5/2) $
 
const double zeta3 =boost::math::constants::zeta_three<double>()
 $ \zeta(3) $
 
const double zeta5 =1.0369277551433699263
 $ \zeta(5) $
 
const double zeta7 =1.0083492773819228268
 $ \zeta(7) $
 
const double sin2_theta_weak =0.23122
 $ \sin^2 \theta_W $ (PDG 2018 value)
 
static const size_t o2scl_mks =1
 MKS units.
 
static const size_t o2scl_cgs =2
 CGS units.
 
const double hc_mev_fm =hc_mev_fm_f<double>()
 $ \hbar c $ in MeV fm (exact)
 
const double hc_mev_cm =hc_mev_fm*1.0e-13
 $ \hbar c $ in MeV cm (exact)
 

Detailed Description

CODATA 2014 values are in Mohr16. CODATA 2018 values are from physics.nist.gov/constants.

Variable Documentation

◆ e2_gaussian

const double o2scl_const::e2_gaussian
Initial value:

In Gaussian Units:

\begin{eqnarray*} &\vec{\nabla} \cdot \vec{E} = 4 \pi \rho \, , \quad \vec{E}=-\vec{\nabla} \Phi \, , \quad \nabla^2 \Phi = - 4 \pi \rho \, , &\\& F=\frac{q_1 q_2}{r^2} \, , \quad W=\frac{1}{2} \int \rho V d^3 x =\frac{1}{8 \pi} \int | \vec{E} |^2 d^3 x \, , \quad \alpha=\frac{e^2}{\hbar c}=\frac{1}{137}& \end{eqnarray*}

Definition at line 945 of file constants.h.

◆ e2_hlorentz

const double o2scl_const::e2_hlorentz =o2scl_const::fine_structure*4.0*pi

In Heaviside-Lorentz units:

\begin{eqnarray*} &\vec{\nabla} \cdot \vec{E} = \rho \, , \quad \vec{E}=-\vec{\nabla} \Phi \, , \quad \nabla^2 \Phi = - \rho \, , &\\& F=\frac{q_1 q_2}{4 \pi r^2} \, , \quad W=\frac{1}{2} \int \rho V d^3 x =\frac{1}{2} \int | \vec{E} |^2 d^3 x \, , \quad \alpha=\frac{e^2}{4 \pi}=\frac{1}{137}& \end{eqnarray*}

Definition at line 967 of file constants.h.

◆ e2_mks

const double o2scl_const::e2_mks =o2scl_mks::electron_charge

In MKS units:

\begin{eqnarray*} &\vec{\nabla} \cdot \vec{E} = \rho \, , \quad \vec{E}=-\vec{\nabla} \Phi \, , \quad \nabla^2 \Phi = - \rho \, , &\\& F=\frac{1}{4 \pi \varepsilon_0}\frac{q_1 q_2}{r^2} \, , \quad W=\frac{1}{2} \int \rho V d^3 x =\frac{\varepsilon_0}{2} \int | \vec{E} |^2 d^3 x \, , \quad \alpha=\frac{e^2}{4 \pi \varepsilon_0 \hbar c}=\frac{1}{137}& \end{eqnarray*}

Note the conversion formulas

\[ q_HL=\sqrt{4 \pi} q_G = \frac{1}{\sqrt{\varepsilon_0}} q_{SI} \]

as mentioned, e.g. in pg. 13 of D. Griffiths Intro to Elem. Particles.

Definition at line 993 of file constants.h.

◆ ec_gauss_fm2

const double o2scl_const::ec_gauss_fm2
Initial value:

Definition at line 999 of file constants.h.

◆ gauss2_fm4

const double o2scl_const::gauss2_fm4
Initial value:

This is useful, e.g. in converting magnetic field squared to an energy density.

Definition at line 1008 of file constants.h.

o2scl_mks::electron_charge
const double electron_charge
A s (derived)
Definition: constants.h:916
o2scl_const::fine_structure
const double fine_structure
Fine structure constant (CODATA 2018 value)
Definition: constants.h:59
o2scl_mks::plancks_constant_hbar
const double plancks_constant_hbar
Planck constant divided by 2 pi in kg m^2 / s.
Definition: constants.h:672
o2scl_const::hc_mev_fm
const double hc_mev_fm
in MeV fm (exact)
Definition: constants.h:135
o2scl_const::ec_gauss_fm2
const double ec_gauss_fm2
1 times the electron charge in Gaussian units in
Definition: constants.h:999

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