| Popis: |
Gravitacijski valovi poznat su fenomen otkriven općom teorijom relativnosti. Nakon prvog Einsteinovog izvoda u lineariziranoj teoriji, njihova fizikalnost bila je upitna više desetljeća. Bondi-Sachsov formalizam otklonio je sumnje i dao baždarno neovisne rezultate u punoj teoriji za asimptotski ravne prostore. Kako su opažanja pokazala da naš svemir nije asimptotski ravan, već ima malu pozitivnu kozmološku konstantu Λ > 0, pokrenuo se razvoj teorije za asimptotski de Sitterove prostore. Iznosimo glavne metode i rezultate za obje vrste prostora i razmatramo poteškoće u razvoju pune teorije u Λ > 0 slučaju. Gravitational waves are a well known phenomenon discovered by the means of general theory of relativity. After Einstein’s first derivation in linearized theory, their physicality was under question for multiple decades. Bondi-Sachs formalism resolved the suspicions and gave gauge independent results in full theory for asymptotically flat spaces. As observations have shown our universe not to be asymptotically flat, but to have a small positive cosmological constant Λ > 0, development of the theory in asymptotically de Sitter spaces began. We present the main methods and results in both cases and study the difficulties in development of the full theory in the Λ > 0 case. |
