CMB Anisotropies, Cosmological Parameters and Fundamental Physics: Current Status & Perspectives

I describe briefly the Cosmic Microwave Background (hereafter CMB) physics which explains why high accuracy observations of its spatial structure are a unique observational tool both for the determination of the global cosmological parameters and to constrain observationally the physics of the early universe. I also briefly survey the many experiments which have measured the anisotropies of the CMB and led to crucial advances in observational Cosmology. The somewhat frantic series of new results has recently culminated with the outcome of the WMAP satellite which confirmed earlier results, set new standards of accuracy, and suggested that the Universe may have reionised earlier than anticipated. Many more CMB experiments are currently taking data or being planned, with the Planck satellite on the 2007 Horizon poised to extract all the cosmological information in the temperature anisotropies, and foray deeply into polarisation.Comment: To appear in the proceedings of "Where Cosmology and Fundamental Physics Meet", 23-26 June, 2003, Marseille, Franc

Poor hand or poor play? the rise and fall of inflation in the U.S.

Inflation in the U.S. rose in the 1970s and fell in the 1980s and 1990s. The conventional story attributes this pattern to changes in monetary policy. Policymakers made errors and learned from them. This article presents the story and existing alternatives that emphasize instead changes beyond the Fed's control. The author also reviews the recent empirical literature on the role played by changes in luck versus changes in policy and finds substantial evidence for both.Inflation (Finance) ; Monetary policy

Lessons from the history of money

This article looks at eight centuries of monetary history and asks: What happened and what have we learned? Money evolved from commodity-based to purely fiduciary, and in the trial-and-error process, governments learned some basic truths about price stability and the management of a sound currency.Money ; Coinage

Dollarization in Argentina

Argentina ; Money ; Gross domestic product

Dollarization in Argentina

Several countries are seriously considering the abandonment of their currency and its formal replacement with the U.S. dollar. Since 1991, Argentina has backed its currency with 100 percent reserves and successfully pegged it to the dollar. In doing so, it has already grappled with many issues that confront would-be adopters of the dollar. Moving to full-fledged dollarization might offer a solution to recurring crises that are partly driven by expectations that Argentina might abandon its peg.Argentina ; Dollar ; Money

Dynamic Factor Price Equalization & International Convergence

We offer a duality-based methodology for incorporating multi-sector effects of international trade into open economy macroeconomic models, developing the concepts of the dynamic factor price equalization set and the integrated intertemporal equilibrium. Under this approach, the aggregate production function depends on output prices and factor endowment stocks. It preserves all of the structure of a standard GDP function from the trade theory literature. In a two-country version of the model considered below, we examine the properties of the dynamic factor price equalization set. If the global economy is initially outside of this set, the equations of motion will pull the economy back into this set. Inside the dynamic FPE set, factor prices are equalized internationally, and with identical tastes and technology, the economy can be regarded as a fully integrated world equilibrium in a dynamic sense (the integrated intertemporal equilibrium). In this equilibrium, all of the standard properties of a closed economy one-sector neoclassical growth model hold, ruling out cycles and chaos, and allowing us to characterize the evolution of international inequality and the persistence of productivity and endowment shocks. Working from the integrated intertemporal equilibrium, we identify properties of persistence linked to inequality and real economic shocks. Cross-country differences in per capita incomes and wealth, and the factor content of trading patterns, may persist over time and even into the new steady state. This provides yet another reason why we might observe lack of income convergence internationally. In addition, real shocks in one country may be transmitted to the other country through factor markets and product prices, and may have persistent effects into the steady-state as well. The model can also generate an endogenous Balassa-Samuelson effect.Neoclassical Models of Trade, Economic Growth of Open Economies, Cross- Country Output Convergence

The big problem of small change

Western Europe was plagued with currency shortages from the 14th century, at which a 'standard formula' had been devised to cure the problem. We use a cash-in-advance model of commodity money to define a currency shortage, show that they could develop and persist under commodity money regime, and analyze the role played by each ingredient in the standard formula. A companion paper documents the evolution of monetary theory, monetary experiments and minting technology over the course of six hundred years.Monetary theory ; Money ; Money theory

Large scale CMB anomalies from thawing cosmic strings

Cosmic strings formed during inflation are expected to be either diluted over super-Hubble distances, i.e., invisible today, or to have crossed our past light cone very recently. We discuss the latter situation in which a few strings imprint their signature in the Cosmic Microwave Background (CMB) Anisotropies after recombination. Being almost frozen in the Hubble flow, these strings are quasi static and evade almost all of the previously derived constraints on their tension while being able to source large scale anisotropies in the CMB sky. Using a local variance estimator on thousand of numerically simulated Nambu-Goto all sky maps, we compute the expected signal and show that it can mimic a dipole modulation at large angular scales while being negligible at small angles. Interestingly, such a scenario generically produces one cold spot from the thawing of a cosmic string loop. Mixed with anisotropies of inflationary origin, we find that a few strings of tension GU = O(1) x 10^(-6) match the amplitude of the dipole modulation reported in the Planck satellite measurements and could be at the origin of other large scale anomalies.Comment: 23 pages, 11 figures, uses jcappub. References added, matches published versio