We show that deviations of the quantum state of the inflaton from the thermal vacuum of inflation may leave an imprint in the CMB anisotropies. The quantum dynamics of the inflaton in such a state produces corrections to the inflationary fluctuations, which may be observable. Because these effects originate from IR physics below the Planck scale, they will dominate over any trans-Planckian impr...

This paper addresses the issue of testing the ‘hybrid’ New Keynesian Phillips Curve (NKPC) through Vector Autoregressive (VAR) systems and likelihood methods, giving special emphasis to the case where the variables are non-stationary. The idea is to use a VAR for both the inflation rate and the explanatory variable(s) to approximate the dynamics of the system and derive testable restrictions. A...

A string motivated, N=1 global supersymmetric, general Lagrangian is obtained that represents an inflaton interacting with the modes of a string. Focus is placed on the Lagrangian’s relevance to warm inflation, which is a cosmology based on dissipative dynamics. Several interaction schemes are identified from the general Lagrangian that may have interesting consequences for dissipative dynamics...

We propose a model for cosmic inflation which is based on an effective description of strongly interacting, nonsupersymmetric matter within the framework of dynamical abelian projection and centerization. The underlying gauge symmetry is assumed to be SU(N) with N≫1. Appealing to a thermodynamical treatment, the ground-state structure of the model is determined by a potential for the inflaton f...

Central bank communication plays an important role in shaping market participants’ expectations. This paper studies a simple nonlinear model of monetary policy in which agents have incomplete information about the economic environment. It shows that agents’ learning and the dynamics of the economy are heavily affected by central bank transparency about its policy rule. A central bank that does ...

Blanchard (2005) suggested that active interest rate policy might induce unstable dynamics in highly-indebted economies. We examine this in a dynamic general equilibrium model where Calvo-type price rigidities provide a rationale for inflation stabilization. Unstable dynamics can occur when the CB is aggressively raising the interest rate in response to higher expected inflation. The constraint...

Standard, slow–roll, single–field inflation, as it has been incorporated into standard cosmology, is an over–simplified scenario to which there have been a number of suggested physical corrections. The generic prediction for the perturbations generated during slow–roll, single–field inflation, as they appear in the cosmic microwave background (CMB), is a flat, close–to– Gaussian spectrum. We ca...

The purpose of this article is to examine the status of a well known argument for a positive rate of steady state inflation. The original argument, by Vickrey (1954) and Phelps (1972), suggests that the economy is more able to dampen shocks, such as fluctuations in the real rate of return on risky capital investment, when inflation rates are positive. The notion is that the conditions required ...