ترغب بنشر مسار تعليمي؟ اضغط هنا

Testing Inflation: A Bootstrap Approach

35   0   0.0 ( 0 )
 نشر من قبل Latham Boyle
 تاريخ النشر 2010
  مجال البحث فيزياء
والبحث باللغة English
 تأليف Latham Boyle




اسأل ChatGPT حول البحث

We note that the essential idea of inflation, that the universe underwent a brief period of accelerated expansion followed by a long period of decelerated expansion, can be encapsulated in a closure condition which relates the amount of accelerated expansion during inflation to the amount of decelerated expansion afterward. We present a protocol for systematically testing the validity of this condition observationally.

قيم البحث

اقرأ أيضاً

We discuss supergravity inflation in braneworld cosmology for the class of potentials $V(phi)=alpha phi^nrm{exp}(-beta^m phi^m)$ with $m=1,~2$. These minimal SUGRA models evade the $eta$ problem due to a broken shift symmetry and can easily accommoda te the observational constraints. Models with smaller $n$ are preferred while models with larger $n$ are out of the $2sigma$ region. Remarkably, the field excursions required for $60$ $e$-foldings stay sub-planckian $Deltaphi <1$.
We study initial conditions for inflation in scenarios where the inflaton potential has a plateau shape. Such models are those most favored by Planck data and can be obtained in a large number of model classes. As a representative example, we conside r Higgs inflation with and without an $R^2$ term in the context of Palatini gravity. We show that inflation with a large number of e-folds generically occurs in a large part of the parameter space without any fine-tuning of parameters even when the scale of inflation and the inflaton field value during inflation are much smaller than the Planck scale. We discuss consequences for detection of primordial gravitational waves and spectral tilt of curvature perturbations, as well as the recently proposed Trans-Planckian Censorship conjecture.
We revisit the notion of slow-roll in the context of general single-field inflation. As a generalization of slow-roll dynamics, we consider an inflaton $phi$ in an attractor phase where the time derivative of $phi$ is determined by a function of $phi $, $dotphi=dotphi(phi)$. In other words, we consider the case when the number of $e$-folds $N$ counted backward in time from the end of inflation is solely a function of $phi$, $N=N(phi)$. In this case, it is found that we need a new independent parameter to properly describe the dynamics of the inflaton field in general, in addition to the standard parameters conventionally denoted by $epsilon$, $eta$, $c_s^2$ and $s$. Two illustrative examples are presented to discuss the non-slow-roll dynamics of the inflaton field consistent with observations.
73 - Taotao Qiu , Yu-Tong Wang 2015
We study a nonsingular bounce inflation model, which can drive the early universe from a contracting phase, bounce into an ordinary inflationary phase, followed by the reheating process. Besides the bounce that avoided the Big-Bang singularity which appears in the standard cosmological scenario, we make use of the Horndesky theory and design the kinetic and potential forms of the lagrangian, so that neither of the two big problems in bouncing cosmology, namely the ghost and the anisotropy problems, will appear. The cosmological perturbations can be generated either in the contracting phase or in the inflationary phase, where in the latter the power spectrum will be scale-invariant and fit the observational data, while in the former the perturbations will have nontrivial features that will be tested by the large scale structure experiments. We also fit our model to the CMB TT power spectrum.
In this paper we show how the string landscape can be constrained using observational data. We illustrate this idea by focusing on Fibre Inflation which is a promising class of string inflationary models in type IIB flux compactifications. We determi ne the values of the microscopic flux-dependent parameters which yield the best fit to the most recent cosmological datasets.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا