Cosmological curvature acceleration
نویسندگان
چکیده
منابع مشابه
Cosmological Acceleration Through Transition to Constant Scalar Curvature
As shown by Parker and Raval, quantum field theory in curved spacetime gives a possible mechanism for explaining the observed recent acceleration of the universe. This mechanism is consistent with a zero cosmological constant, and causes the universe to make a transition to an accelerating expansion in which the scalar curvature, R, of spacetime remains constant. We show that this model agrees ...
متن کاملCurvature Corrections as the Source of the Cosmological Acceleration
Corrections to Einstein’s equations that become important at small curvatures are considered. The field equations are derived using a Palatini variation in which the connection and metric are varied independently. In contrast to the Einstein-Hilbert variation, which yields fourth order equations, the Palatini approach produces second order equations in the metric. The Lagrangian L(R) = R− α/R i...
متن کامل1/R Curvature Corrections as the Source of the Cosmological Acceleration
Corrections to Einstein’s equations that become important at small curvatures are considered. The field equations are derived using a Palatini variation in which the connection and metric are varied independently. In contrast to the Einstein-Hilbert variation, which yields fourth order equations, the Palatini approach produces second order equations in the metric. The Lagrangian L(R) = R− α/R i...
متن کاملCosmological acceleration from structure formation
We discuss the Buchert equations, which describe the average expansion of an inhomogeneous dust universe. In the limit of small perturbations, they reduce to the Friedmann-Robertson-Walker equations. However, when the universe is very inhomogeneous, the behaviour can be qualitatively different from the FRW case. In particular, the average expansion rate can accelerate even though the local expa...
متن کاملA Measure of Cosmological Acceleration
We propose quantifying the quantum gravitational back-reaction on inflation with an invariant measure of the local acceleration rather than the expansion rate. Our observable is suitable for models in which there is no scalar inflaton to provide a preferred velocity field with which to define the expansion. As an example, we use stochastic techniques to evaluate the local acceleration at one lo...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The European Physical Journal Special Topics
سال: 2021
ISSN: 1951-6355,1951-6401
DOI: 10.1140/epjs/s11734-021-00194-x