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Title: Open EFTs, IR effects & late-time resummations: systematic corrections in stochastic inflation

Though simple inflationary models describe the CMB well, their corrections are often plagued by infrared effects that obstruct a reliable calculation of late-time behaviour. Here we adapt to cosmology tools designed to address similar issues in other physical systems with the goal of making reliable late-time inflationary predictions. The main such tool is Open EFTs which reduce in the inflationary case to Stochastic Inflation plus calculable corrections. We apply this to a simple inflationary model that is complicated enough to have dangerous IR behaviour yet simple enough to allow the inference of late-time behaviour. We find corrections to standard Stochastic Inflationary predictions for the noise and drift, and we find these corrections ensure the IR finiteness of both these quantities. The late-time probability distribution, P(Φ), for super-Hubble field fluctuations are obtained as functions of the noise and drift and so these too are IR finite. We compare our results to other methods (such as large-N models) and find they agree when these models are reliable. In all cases we can explore in detail we find IR secular effects describe the slow accumulation of small perturbations to give a big effect: a significant distortion of the late-time probability distribution for themore » field. But the energy density associated with this is only of order H 4 at late times and so does not generate a dramatic gravitational back-reaction.« less
 [1] ;  [2] ;  [3]
  1. McMaster Univ., Hamilton, ON (Canada). Physics & Astronomy; Perimeter Inst. for Theoretical Physics, Waterloo, ON (Canada)
  2. Carnegie Mellon Univ., Pittsburgh, PA (United States). Physics Dept.
  3. Swansea Univ., Swansea (United Kingdom). Dept. of Physics
Publication Date:
Grant/Contract Number:
FG03-91ER40682; FG02-91ER40682
Accepted Manuscript
Journal Name:
Journal of High Energy Physics (Online)
Additional Journal Information:
Journal Name: Journal of High Energy Physics (Online); Journal Volume: 2016; Journal Issue: 1; Journal ID: ISSN 1029-8479
Springer Berlin
Research Org:
McMaster Univ., Hamilton, ON (Canada)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25); Natural Sciences and Engineering Research Council of Canada (NSERC); National Science Foundation (NSF)
Country of Publication:
United States
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; Cosmology of Theories beyond the SM; Effective field theories; Classical Theories of Gravity; Stochastic Processes
OSTI Identifier: