Dimensional reduction of the massless limit of the linearized "New Massive Gravity"

The so called "New Massive Gravity" in $D=2+1$ consists of the Einstein-Hilbert action (with minus sign) plus a quadratic term in curvatures ($K$-term). Here we perform the Kaluza-Klein dimensional reduction of the linearized $K$-term to $D=1+1$. We end up with a fourth-order massive electrodynamics in $D=1+1$ described by a rank-2 tensor. Remarkably, there appears a local symmetry in $D=1+1$ which persists even after gauging away the Stueckelberg fields of the dimensional reduction. It plays the role of a $U(1)$ gauge symmetry. Although of higher-order in derivatives, the new $2D$ massive electrodynamics is ghost free, as we show here. It is shown, via master action, to be dual to the Maxwell-Proca theory with a scalar Stueckelberg field.Comment: 12 pages, one more reference and text slightly modified accordingl

Is the US Fiscal Deficit Sustainable? A Fractionally Integrated and Cointegrated Approach

The sustainability of fiscal deficits has received in recent years increasing attention from economists. Empirical work has concentrated on both the univariate properties of debt and the cointegration properties of public revenues and expenditures. In this paper, we examine if sustainability of the US fiscal deficit holds by means of studying the univariate properties of the difference between public revenues and expenditures. However, instead of using classical approaches based on I(1) or I(0) integration techniques, we use a methodology based on fractional processes. The results show that the public deficit in the US is an I(d) process with d slightly smaller than 1, implying that fiscal deficit is mean reverting, and thus, sustainable, though the adjustment process towards equilibrium will take a very long time.

Additional Empirical Evidence on Real Convergence: A Fractionally Integrated Approach

This article examines the real convergence hypothesis in 15 OECD countries. For this purpose, we examine the order of integration of the real GDP per capita series in these countries as well as their differences with respect to the US which is used as a benchmark country. We use both parametric and semiparametric methods and the results show that convergence is only achieved in half of the countries, namely, Austria, Australia, Canada, Finland, Germany, Japan and the UK. On the contrary, the results for Belgium, Denmark, France, Italy, the Netherlands, Norway and Sweden show strong evidence against this hypothesis.

Fermionic dark matter-photon quantum interaction: A mechanism for darkness

ELKO fermionic fields are prime candidates to describe dark matter, due to their intrinsic neutral nature, as they are constructed as eigenstates of the charge conjugation operator with dual helicity. To formulate the meaning of the darkness, the ELKO-photon coupling is scrutinized with a Pauli-like interaction, and the path integral is then formulated from the phase space constraint structure. Ward-Takahashi-like identities and Schwinger-Dyson equations, together with renormalizability, are employed to investigate a phenomenological mechanism to avoid external light signals. Accordingly, the non-polarized pair annihilation and Compton-like processes are shown to vanish at the limit of small scattering angles even if considering 1-loop radiative corrections, reinforcing the ELKO dark matter interpretation. However, ELKO interactions with nucleons are still possible. Motivated by recent nucleon-recoil experiments to detect dark matter, we furnish a consistent theoretical setup to describe ELKO-photon interaction compatible with the prevalence of darkness.Comment: 42 pages, 6 figure

Time Series

This paper first shows that survey-based expectations (SBE) outperform standard time series models in U.S. quarterly inflation out-of-sample prediction and that the term structure of survey-based inflation forecasts has predictive power over the path of future inflation changes. It then proposes some empirical explanations for the forecasting success of survey-based inflation expectations. We show that SBE pool a large amount of heterogeneous information on inflation expectations and react more flexibly and accurately to macro conditions both contemporaneously and dynamically. We illustrate the flexibility of SBE forecasts in the context of the recent financial crisis

Generalized Stueckelberg-Higgs gauge theories

The aim of this work is to discuss and explorer some generalized aspects of generation of photon mass respecting gauge symmetry. So with this intention we introduce the generalized Stueckelberg and Higgs gauge theories and present the classical and quantum conceptual aspects. We construct the quantum theory by writing the transition amplitude in the Fadeev-Senjanovic formalism and put it in a covariant form by the Fadeev-Popov method. Posteriorly we analyze the independence of physics by gauge choices via BRST symmetry. As we will see, the Stueckelberg structure has influence in the quantization process of the Higgs theory in the Gerardus 't Hooft shape, in which we see an intimate relationship between the Stueckelberg compensating field and the Goldstone boson. The degrees of freedom are explored not only in the quantization process, due to the constraints in gauge theories, but also in the Goldstone theorem, wherein we understand how the generalized gauge field eat the Goldstone boson and acquire mass

Banks’ Net Interest Margin in the 2000s: A Macro-Accounting International Perspective

This paper re-examines the determinants of Net Interest Margin (NIM) in the banking industries of 15 developed and emerging economies. It presents three main contributions with respect to previous studies: first, we analyze the determinants of NIM in the years leading to the 2008 financial crisis; second, we account for the role of different accounting standards across countries; third, we use multi-way cluster estimation methodologies which control for cross-sectional and time-series dependence in macroeconomic and banking variables. We find that the introduction of International Financial Reporting Standards (IFRSs) contributed to lower NIM variations unexplained by standard accounting variables. Interest rate volatility is found to be positively and strongly related to NIM dynamics, whereas inflation risk is often found to be a relevant driver of NIM crosscountry differences

Bio‐Based Polyurethanes from Carbohydrate Monomers

The production of sustainable and environmentally friendly materials constitutes a growing field of attention. The incorporation of sugar‐derived units into traditional step‐growth polymers such as polyamides, polyesters, and polyurethanes is a healthy method to prepare novel biodegradable and biocompatible materials for application in the biomedical field and other sectors such as foodstuff packaging