| （英） |
To investigate the effect of quantum gravity, the behavior of the entropy is important.
From the principle of holography, the entropy in the finite region is bounded by the area of its boundary. However, there are some models breaking the entropy bound and occuring information problem such as, the black hole and de Sitter spacetime, that is the model of expanding universe.
To more concretely understand the entropy bound in de Sitter spacetime from the aspect of quantum information, we trace the recent progress for the black hole information loss paradox.
Especially, in the context of the black hole, there is the Page curve. The Page curve is considered as the typical behavior of entropy in the process of the black hole evaporation. Therefore we will consider the typical begavior of entropy in de SItter spacetime.
To attack the objective, we use the model of stochastic inflation. In this model, we can treat the quantum system for the inflaton, that is control the inflation, as classical stochastic system. Using this, firstly, we reformulate the violation of entropy bound. Indeed, because the volume is the typical physical quantity in the expanding universe, taking volume-weighting for the state, we gain the typical state of inflaton. Finally we gain the curve which the behavior of entropy should form. |