English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

In this work, we study the impact of quantum entanglement on the two-pointcorrelation function and the associated primordial power spectrum of meansquare vacuum fluctuation in a bipartite quantum field theoretic system. Thefield theory that we consider is the effective theory of axion field arisingfrom Type IIB string theory compactified to four dimensions. We compute theexpression for the power spectrum of vacuum fluctuation in three differentapproaches, namely (1) field operator expansion (FOE) technique with thequantum entangled state, (2) reduced density matrix (RDM) formalism with mixedquantum state and (3) the method of non-entangled state (NES). For masslessaxion field, in all these three formalism, we reproduce, at the leading order,the exact scale-invariant power spectrum which is well known in the literature.We observe that due to quantum entanglement, the sub-leading terms for thesethee formalisms are different. Thus, such correction terms break the degeneracyamong the analysis of the FOE, RDM and NES formalisms in the super-horizonlimit. On the other hand, for massive axion field, we get a slight deviationfrom scale invariance and exactly quantify the spectral tilt of the powerspectrum in small scales. Apart from that, for massless and massive axionfield, we find distinguishable features of the power spectrum for the FOE, RDM,and NES on the large scales, which is the result of quantum entanglement. Wealso find that such large-scale effects are comparable to or greater than thecurvature radius of the de Sitter space. Most importantly, in the near future,if experiments probe for early universe phenomena, one can detect such smallquantum effects. In such a scenario, it is possible to test the implications ofquantum entanglement in primordial cosmology.

universe

Cosmological spectrum of two-point correlation function from vacuum  fluctuation of Stringy Axion field in De Sitter space: A study of the role of  Quantum Entanglement