Geroch energy
   HOME

TheInfoList



OR:

The Geroch energy or Geroch mass is one of the possible definitions of
mass Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different ele ...
in
general relativity General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics ...
. It can be derived from the Hawking energy, itself a measure of the bending of ingoing and outgoing rays of
light Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 t ...
that are
orthogonal In mathematics, orthogonality is the generalization of the geometric notion of '' perpendicularity''. By extension, orthogonality is also used to refer to the separation of specific features of a system. The term also has specialized meanings in ...
to a 2-
sphere A sphere () is a geometrical object that is a three-dimensional analogue to a two-dimensional circle. A sphere is the set of points that are all at the same distance from a given point in three-dimensional space.. That given point is the c ...
surrounding the region of space whose mass is to be defined, by leaving out certain (positive) terms related to the sphere's external and internal
curvature In mathematics, curvature is any of several strongly related concepts in geometry. Intuitively, the curvature is the amount by which a curve deviates from being a straight line, or a surface deviates from being a plane. For curves, the can ...
. The equation for the mass of a 2-sphere is based on the equation for the ingoing and outgoing ray of light corresponding to an electron on its surface, expressed as: γ = 2 γ. The inverse of this equation represents the value of the Hawking energy , and the result is the mass of an entangled pair of photons: the two photons can not be entangled if only they are located at the same location on the surface. But in this case, both photons must be propagating simultaneously. So the two photons, or their antiparticles, must be travelling through a field that is 3-dimensional, and the field can be regarded as containing the mass of another point.Section 6.2 in


See also

* Mass in general relativity *
Robert Geroch Robert Geroch (born 1 June 1942 in Akron, Ohio) is an American theoretical physicist and professor at the University of Chicago. He has worked prominently on general relativity and mathematical physics and has promoted the use of category theor ...


References

General relativity Mass {{relativity-stub