scholarly journals Consistency relation and inflaton field redefinition in the δN formalism

2017 ◽  
Vol 769 ◽  
pp. 413-417 ◽  
Author(s):  
Guillem Domènech ◽  
Jinn-Ouk Gong ◽  
Misao Sasaki
Keyword(s):  
Inflaton Field ◽  
Consistency Relation ◽  
Field Redefinition

Field redefinition and on-shell renormalisation

1983 ◽  
Vol 221 (1) ◽  
pp. 178-194 ◽  
Author(s):  
G. Bonneau
Keyword(s):  
Field Redefinition

scholarly journals Inflationary birefringence and baryogenesis

2016 ◽  
Vol 25 (11) ◽  
pp. 1640013 ◽  
Author(s):  
Stephon Alexander
Keyword(s):  
Gravitational Waves ◽  
Lepton Number ◽  
Gauge Fields ◽  
Lepton Asymmetry ◽  
Complex Phase ◽  
Inflaton Field ◽  
Model Based ◽  
Cross Correlations ◽  
Chern Simons

A decade ago, the first leptogenesis model based on inflation was proposed, where the complex phase of the inflaton field carries lepton number [S. H. S. Alexander, M. E. Peskin and M. M. Sheikh-Jabbari, Phys. Rev. Lett. 96 (2006) 081301, arXiv:hep-th/0403069 ]. If the inflaton field is an axion, it can couple to gravitational waves and gauge fields via Chern–Simons invariants. Due to these couplings, birefringent gravitational and gauge primordial perturbations are created during inflation to generate a lepton asymmetry, establishing a possible connection between nonvanishing TB-parity-violating polarization cross-correlations and leptogenesis. We also discuss the prospect for a subset of these models which can directly source circular (V-mode) polarization in the CMB.

scholarly journals Holographic entanglement entropy, field redefinition invariance, and higher derivative gravity theories

2016 ◽  
Vol 94 (4) ◽  
Author(s):  
M. R. Mohammadi Mozaffar ◽  
A. Mollabashi ◽  
M. M. Sheikh-Jabbari ◽  
M. H. Vahidinia
Keyword(s):  
Entanglement Entropy ◽  
Holographic Entanglement Entropy ◽  
Higher Derivative ◽  
Gravity Theories ◽  
Field Redefinition

scholarly journals A generalized non-Gaussian consistency relation for single field inflation

2018 ◽  
Vol 2018 (05) ◽  
pp. 024-024 ◽  
Author(s):  
Rafael Bravo ◽  
Sander Mooij ◽  
Gonzalo A. Palma ◽  
Bastián Pradenas
Keyword(s):  
Consistency Relation ◽  
Single Field ◽  
Non Gaussian

scholarly journals POWER-SUPPRESSED THERMAL EFFECTS FROM HEAVY PARTICLES

2001 ◽  
Vol 16 (supp01c) ◽  
pp. 1287-1290
Author(s):  
YU JIA
Keyword(s):  
Thermal Effects ◽  
Light Field ◽  
Boltzmann Factor ◽  
Heavy Particles ◽  
Hamiltonian Density ◽  
Effective Interactions ◽  
Effective Lagrangian ◽  
Pair Annihilation ◽  
Light Particles ◽  
Field Redefinition

In quantum field theory, heavy particles with mass M much greater than the temperature T give not only effects suppressed by the Boltzmann factor e-M/T, but also effects suppressed by powers of T/M. We show that power-suppressed terms in equilibrium observables arise from effective interactions among light particles due to virtual heavy particles. We study a model introduced by Matsumoto and Yoshimura in which heavy bosons interact only through a term that allows pair annihilation into light particles. We construct an effective Lagrangian for the light field by integrating out the heavy field, and use it to calculate the leading power-suppressed terms in the energy density. The thermal average of the Hamiltonian density for the heavy field includes a term proportional to T6/M2, but we show that this term can be eliminated by a field redefinition and therefore cannot have any physical significance.

scholarly journals Are there really conformal frames? Uniqueness of affine inflation

2018 ◽  
Vol 27 (09) ◽  
pp. 1830006 ◽  
Author(s):  
Hemza Azri
Keyword(s):  
Affine Connection ◽  
Scalar Fields ◽  
A Posteriori ◽  
Nonminimal Coupling ◽  
Metric Tensor ◽  
Coupling Dynamics ◽  
Conformal Frames ◽  
Affine Gravity ◽  
Inflationary Models ◽  
Field Redefinition

Here, we concisely review the nonminimal coupling dynamics of a single scalar field in the context of purely affine gravity and extend the study to multifield dynamics. The coupling is performed via an affine connection and its associated curvature without referring to any metric tensor. The latter arises a posteriori and it may gain an emergent character like the scale of gravity. What is remarkable in affine gravity is the transition from nonminimal to minimal couplings which is realized by only field redefinition of the scalar fields. Consequently, the inflationary models gain a unique description in this context where the observed parameters, like the scalar tilt and the tensor-to-scalar ratio, are invariant under field reparametrization. Overall, gravity in its affine approach is expected to reveal interesting and rich phenomenology in cosmology and astroparticle physics.

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