scholarly journals Observational constraints on an inflation model with a running mass

1999 ◽  
Vol 60 (2) ◽  
Author(s):  
Laura Covi ◽  
David H. Lyth ◽  
Leszek Roszkowski
Keyword(s):  
Observational Constraints ◽  
Inflation Model

Inflationary cosmology: First 30+ years

2015 ◽  
Vol 24 (11) ◽  
pp. 1530025 ◽  
Author(s):  
Katsuhiko Sato ◽  
Jun'ichi Yokoyama
Keyword(s):  
Inflationary Cosmology ◽  
Observational Constraints ◽  
Inflation Model ◽  
Common Framework ◽  
Single Field ◽  
The Many ◽  
Historical Developments ◽  
Inflationary Models

Starting with an account of historical developments in Japan and Russia, we review inflationary cosmology and its basic predictions in a pedagogical manner. We also introduce the generalized G-inflation model, in terms of which all the known single-field inflation models may be described. This formalism allows us to analyze and compare the many inflationary models that have been proposed simultaneously and within a common framework. Finally, current observational constraints on inflation are reviewed, with particular emphasis on the sensitivity of the inferred constraints to the choice of datasets used.

scholarly journals WMAP5 OBSERVATIONAL CONSTRAINTS ON BRANEWORLD NEW INFLATION MODEL

2010 ◽  
Vol 25 (01) ◽  
pp. 171-183 ◽  
Author(s):  
R. ZARROUKI ◽  
Z. SAKHI ◽  
M. BENNAI
Keyword(s):  
High Energy ◽  
Observational Constraints ◽  
Type Ii ◽  
Energy Limit ◽  
High Energy Limit ◽  
Inflation Model ◽  
Slow Roll ◽  
Braneworld Model ◽  
Perturbation Spectrum ◽  
Good Agreement

We study a new inflation potential in the framework of the Randall–Sundrum type II braneworld model. Using the technic developed in Ref. 1, we consider both a monomial and a new inflation potentials and apply the slow-roll approximation in high energy limit, to derive analytical expression of relevant perturbation spectrum. We show that for some values of the parameter n in the potential [Formula: see text] we obtain a perturbation spectrum which gives a good agreement with the recent WMAP5 observations.

A SIMPLE QUINTESSENTIAL INFLATION MODEL

2009 ◽  
Vol 24 (08n09) ◽  
pp. 1639-1642 ◽  
Author(s):  
M. C. BENTO ◽  
R. GONZÁLEZ FELIPE ◽  
N. M. C. SANTOS
Keyword(s):  
Scalar Field ◽  
Simple Model ◽  
Parameter Space ◽  
Observational Constraints ◽  
Exponential Potential ◽  
Wide Region ◽  
Present Epoch ◽  
Inflation Model

A simple model of quintessential inflation with the modified exponential potential e-αϕ[A + (ϕ-ϕ0)2] is analyzed in the braneworld context. Considering reheating via instant preheating, the evolution of the scalar field from inflation to the present epoch is consistent with the observational constraints in a wide region of the parameter space.

Observational Constraints on Models of the Solar Background Spectrum

1999 ◽  
Vol 516 (2) ◽  
pp. 939-945 ◽  
Author(s):  
Th. Straus ◽  
G. Severino ◽  
F.‐L. Deubner ◽  
B. Fleck ◽  
S. M. Jefferies ◽  
...  
Keyword(s):  
Observational Constraints ◽  
Background Spectrum

A Realistic Grid of Models for the Gravitationally Lensed Einstein Cross (Q2237+0305) and Its Relation to Observational Constraints

1998 ◽  
Vol 495 (2) ◽  
pp. 609-616 ◽  
Author(s):  
Kyu‐Hyun Chae ◽  
David A. Turnshek ◽  
Valery K. Khersonsky
Keyword(s):  
Observational Constraints

scholarly journals CHAOTIC INFLATION ON THE RANDALL–SUNDRUM TWO-BRANE MODEL

2010 ◽  
Vol 25 (31) ◽  
pp. 2697-2713
Author(s):  
KOUROSH NOZARI ◽  
SIAMAK AKHSHABI
Keyword(s):  
Scalar Field ◽  
Field Potential ◽  
Friedmann Equation ◽  
Warp Factor ◽  
Model Parameters ◽  
Stabilization Mechanism ◽  
Brane Model ◽  
Inflation Model ◽  
Bulk Scalar Field ◽  
Chaotic Inflation

We construct an inflation model on the Randall–Sundrum I (RSI) brane where a bulk scalar field stabilizes the inter-brane separation. We study impact of the bulk scalar field on the inflationary dynamics on the brane. We proceed in two different approaches: in the first approach, the stabilizing field potential is directly appeared in the Friedmann equation and the resulting scenario is effectively a two-field inflation. In the second approach, the stabilization mechanism is considered in the context of a warp factor so that there is just one field present that plays the roles of both inflaton and stabilizer. We study constraints imposed on the model parameters from recent observations.

scholarly journals Magnetospheric Structure of Rotation-Powered Neutron Stars

1992 ◽  
Vol 128 ◽  
pp. 56-77 ◽  
Author(s):  
Jonathan Arons
Keyword(s):  
Radio Emission ◽  
Gamma Radiation ◽  
Heavy Ions ◽  
Theoretical Work ◽  
Future Research ◽  
Observational Constraints ◽  
Polar Caps ◽  
Recent Theoretical Work ◽  
Density Flow ◽  
Promising Avenue

AbstractI survey recent theoretical work on the structure of the magnetospheres of rotation-powered pulsars, within the observational constraints set by their observed spindown, their ability to power synchrotron nebulae and their ability to produce beamed collective radio emission, while putting only a small fraction of their energy into incoherent X- and gamma radiation. I find no single theory has yet given a consistent description of the magnetosphere, but I conclude that models based on a dense outflow of pairs from the polar caps, permeated by a lower density flow of heavy ions, are the most promising avenue for future research.

scholarly journals Can the Local Bubble explain the radio background?

2021 ◽  
Vol 502 (2) ◽  
pp. 2807-2814
Author(s):  
Martin G H Krause ◽  
Martin J Hardcastle
Keyword(s):  
Magnetic Field ◽  
Energy Density ◽  
Radio Emission ◽  
Magnetic Energy ◽  
Cosmic Ray ◽  
Observational Constraints ◽  
Local Bubble ◽  
Magnetic Energy Density ◽  
Magnetic Field Model ◽  
Radio Background

ABSTRACT The ARCADE 2 balloon bolometer along with a number of other instruments have detected what appears to be a radio synchrotron background at frequencies below about 3 GHz. Neither extragalactic radio sources nor diffuse Galactic emission can currently account for this finding. We use the locally measured cosmic ray electron population, demodulated for effects of the Solar wind, and other observational constraints combined with a turbulent magnetic field model to predict the radio synchrotron emission for the Local Bubble. We find that the spectral index of the modelled radio emission is roughly consistent with the radio background. Our model can approximately reproduce the observed antenna temperatures for a mean magnetic field strength B between 3 and 5 nT. We argue that this would not violate observational constraints from pulsar measurements. However, the curvature in the predicted spectrum would mean that other, so far unknown sources would have to contribute below 100 MHz. Also, the magnetic energy density would then dominate over thermal and cosmic ray electron energy density, likely causing an inverse magnetic cascade with large variations of the radio emission in different sky directions as well as high polarization. We argue that this disagrees with several observations and thus that the magnetic field is probably much lower, quite possibly limited by equipartition with the energy density in relativistic or thermal particles (B = 0.2−0.6 nT). In the latter case, we predict a contribution of the Local Bubble to the unexplained radio background at most at the per cent level.

Observational constraints on low cloud feedback reduce uncertainty of climate sensitivity

2021 ◽  
Author(s):  
Timothy A. Myers ◽  
Ryan C. Scott ◽  
Mark D. Zelinka ◽  
Stephen A. Klein ◽  
Joel R. Norris ◽  
...  
Keyword(s):  
Climate Sensitivity ◽  
Cloud Feedback ◽  
Observational Constraints ◽  
Low Cloud
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