83XX 


Relativity and gravitational theory 

83Cxx 

General relativity 


83C05 
Einstein's equations (general structure, canonical formalism, Cauchy problems) 


83C10 
Equations of motion 


83C15 
Exact solutions 


83C20 
Classes of solutions; algebraically special solutions, metrics with symmetries 


83C22 
EinsteinMaxwell equations 


83C25 
Approximation procedures, weak fields 


83C27 
Lattice gravity, Regge calculus and other discrete methods 


83C30 
Asymptotic procedures (radiation, news functions, {\scr H}spaces, etc.) 


83C35 
Gravitational waves 


83C40 
Gravitational energy and conservation laws; groups of motions 


83C45 
Quantization of the gravitational field 


83C47 
Methods of quantum field theory [See also 81T20] 


83C50 
Electromagnetic fields 


83C55 
Macroscopic interaction of the gravitational field with matter (hydrodynamics, etc.) 


83C57 
Black holes 


83C60 
Spinor and twistor methods; NewmanPenrose formalism 


83C65 
Methods of noncommutative geometry [See also 58B34] 


83C75 
Spacetime singularities, cosmic censorship, etc. 


83C80 
Analogues in lower dimensions 


83C99 
None of the above, but in this section 