scholarly journals Induced fermionic currents in de Sitter spacetime in the presence of a compactified cosmic string

2015 ◽  
Vol 32 (13) ◽  
pp. 135002 ◽  
Author(s):  
A Mohammadi ◽  
E R Bezerra de Mello ◽  
A A Saharian
Keyword(s):  
Cosmic String ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Sitter Spacetime

scholarly journals Fermionic vacuum polarization by a cosmic string in anti-de Sitter spacetime

2013 ◽  
Vol 30 (17) ◽  
pp. 175001 ◽  
Author(s):  
E R Bezerra de Mello ◽  
E R Figueiredo Medeiros ◽  
A A Saharian
Keyword(s):  
Cosmic String ◽  
Vacuum Polarization ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Sitter Spacetime

scholarly journals Vacuum bosonic currents induced by a compactified cosmic string in dS background

2020 ◽  
Vol 29 (15) ◽  
pp. 2050103
Author(s):  
E. A. F. Bragança ◽  
E. R. Bezerra de Mello ◽  
A. Mohammadi
Keyword(s):  
Cosmic String ◽  
Axial Current ◽  
Wave Functions ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Fermionic Field ◽  
Sitter Spacetime ◽  
Compact Dimension ◽  
Complete Set ◽  
Current Densities

In this paper, we study the vacuum bosonic currents in the geometry of a compactified cosmic string in the background of the de Sitter spacetime. The currents are induced by magnetic fluxes, one running along the cosmic string and another one enclosed by the compact dimension. To develop the analysis, we obtain the complete set of normalized bosonic wave functions obeying a quasiperiodicity condition. In this context, we calculate the azimuthal and axial current densities and we show that these quantities are explicitly decomposed into two contributions: one originating from the geometry of a straight uncompactified cosmic string and the other induced by the compactification. We also compare the results with the literature in the case of a massive fermionic field in the same geometry.

scholarly journals Unimodular vs nilpotent superfield approach to pure dS supergravity

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Sukruti Bansal ◽  
Silvia Nagy ◽  
Antonio Padilla ◽  
Ivonne Zavala
Keyword(s):  
String Theory ◽  
General Framework ◽  
Recent Progress ◽  
High Energy ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
New Approach ◽  
Sitter Spacetime ◽  
Novel Approach ◽  
De Sitter Vacua

Abstract Recent progress in understanding de Sitter spacetime in supergravity and string theory has led to the development of a four dimensional supergravity with spontaneously broken supersymmetry allowing for de Sitter vacua, also called de Sitter supergravity. One approach makes use of constrained (nilpotent) superfields, while an alternative one couples supergravity to a locally supersymmetric generalization of the Volkov-Akulov goldstino action. These two approaches have been shown to give rise to the same 4D action. A novel approach to de Sitter vacua in supergravity involves the generalisation of unimodular gravity to supergravity using a super-Stückelberg mechanism. In this paper, we make a connection between this new approach and the previous two which are in the context of nilpotent superfields and the goldstino brane. We show that upon appropriate field redefinitions, the 4D actions match up to the cubic order in the fields. This points at the possible existence of a more general framework to obtain de Sitter spacetimes from high-energy theories.

scholarly journals Wavefunctions in dS/CFT revisited: principal series and double-trace deformations

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Hiroshi Isono ◽  
Hoiki Madison Liu ◽  
Toshifumi Noumi
Keyword(s):  
Principal Series ◽  
Light Fields ◽  
Quadratic Term ◽  
De Sitter Spacetime ◽  
Cosmological Horizon ◽  
De Sitter ◽  
Complementary Series ◽  
Point Function ◽  
Sitter Spacetime ◽  
Simple Scaling

Abstract We study wavefunctions of heavy scalars on de Sitter spacetime and their implications to dS/CFT correspondence. In contrast to light fields in the complementary series, heavy fields in the principal series oscillate outside the cosmological horizon. As a consequence, the quadratic term in the wavefunction does not follow a simple scaling and so it is hard to identify it with a conformal two-point function. In this paper, we demonstrate that it should be interpreted as a two-point function on a cyclic RG flow which is obtained by double-trace deformations of the dual CFT. This is analogous to the situation in nonrelativistic AdS/CFT with a bulk scalar whose mass squared is below the Breitenlohner-Freedman (BF) bound. We also provide a new dS/CFT dictionary relating de Sitter two-point functions and conformal two-point functions in the would-be dual CFT.

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