Astrophysics (Index) | About |

A **power law** in statistics is a relationship between
quantities where one is proportional to the power of the other.
Often such relations only hold over a given range.
Template (for quantities *x* and *y*):

y=ax^{k}

Subtypes include "square law" and "inverse-square law". Some physics examples:

- Stefan-Boltzmann law (black-body radiation power versus temperature).
- Newtonian gravity.
- Electrostatics.
- Kepler's third law.
- Initial mass function of stars.

A **power law spectrum** is an EMR spectrum such that the flux at each
frequency is related to that frequency by a power law, the
exponent being referred to as its spectral index.
Such a spectrum can only fit this description over a particular
regime, lest it reach infinities.
Synchrotron radiation is described as such a power law spectrum.
The **black-body spectrum** is not, peaking in the center,
but its longer-wavelength
portion is usefully treated as a power law spectrum.
Cosmic rays' spectrum is basically power law.

http://en.wikipedia.org/wiki/Power_law

Compton reflection

cosmic rays (CR)

dense core mass function (DCMF)

luminosity function (LF)

radio relics

spectral index (α)

synchrotron radiation