http://arxiv.org/abs/1712.08299
In this work, we study the phenomena of quantum entanglement by computing de Sitter entanglement entropy from Von Newmann measure. For this purpose we consider a bipartite quantum field theoretic setup in presence of axion originating from ${\bf Type~ II~B}$ string theory. We consider the initial vaccum to be CPT invariant non adiabatic $\alpha$ vacua state under ${\bf SO(1,4)}$ ismometry, which is characterized by a real one parameter family. To implement this technique we use a ${\bf S^2}$ which divide the de Sitter into two exterior and interior sub regions. First we derive the wave function of axion in an open chart for $\alpha$ vacua by applying Bogoliubov transformation on the solution for Bunch Davies vacuum state. Further we quantify the density matrix by tracing over the contribution from exterior region. Using this result we derive entanglement entropy, R$\acute{e}$nyi entropy and explain the long range quantum effects in primordial cosmological correlations. We also provide a comparison between the results obtained from Bunch Davies vacuum and the generalized $\alpha$ vacua, which implies that the amount of quantum entanglement and the long range effects are larger for non zero value of the parameter $\alpha$. Most significantly, our derived results for $\alpha$ vacua provides the necessary condition for generating non zero entanglement entropy in primordial cosmology.
S. Choudhury and S. Panda
Mon, 25 Dec 17
14/37
Comments: 68 pages, 26 figures, 9 tables
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