RG-2 flow, mass and entropy
| Autor: | Oscar Lasso Andino |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Physics
Mathematics - Differential Geometry Physics and Astronomy (miscellaneous) Sigma model General relativity Entropy (statistical thermodynamics) Space time Mathematical analysis FOS: Physical sciences Ricci flow General Relativity and Quantum Cosmology (gr-qc) Renormalization group Curvature General Relativity and Quantum Cosmology Physics::Fluid Dynamics Differential Geometry (math.DG) FOS: Mathematics Asymptotically flat spacetime |
| Popis: | The RG-2 flow is the two-loop approximation for the world-sheet non-linear sigma model renormalization group flow. The first truncation of the flow is the well known Ricci flow, at two loops higher order curvature terms appear, changing almost completely the behaviour of the evolution equation. In this article we study the RG-2 flow in the context of general relativity. Contrary to what happens with the Ricci flow the RG-2 flow theory has not been studied exhaustively, and from a mathematical point of view there are big differences between both flows. Considering a time symmetric foliation of an asymptotically flat spacetime, we show that the area $A$ of a closed two dimensional surface $S$ is monotonous under the RG-2 flow, refining and extending the previous results already known for the Ricci flow. We show that the inequality that relates the area of the surface $S$ and the Hawking mass, already found for the Ricci flow, is still satisfied when we make evolve the area under the new flow. Finally, we discuss about Perelman`s $W$-entropy for the RG-2 flow and the physically motivated path towards the gradient formulation of the RG-2 flow. Typos corrected, references added |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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