How useful is the Theoretical and Empirical Growth Literature for Policies in the Developing Countries?

This paper examines a recent view of Pritchett (2006) that there is a wide gap between the theoretical and empirical growth literature and the policy needs of the developing countries. Growth literature has focussed on the long term growth outcomes but policy makers of the developing countries need rapid improvements in the growth rate in the short to medium terms. We think that this gap can be reduced if attention is given to the dynamic effects of policies. With data on Singapore, Malaysia and Thailand we show that an extended version of the Solow (1956) model is well suited for this purpose. We found that the short to medium term growth effects of investment ratio are much higher than its long run effects and persist. Dynamic simulations for Singapore showed that these short and medium run growth effects are significantly higher than the steady state growth rate for up to 10 years.Solow Growth Model, Endogenous Growth, Dynamic Growth Effects of Investment Rate, Policies for Developing Countries.

Tomographic Intensity Mapping versus Galaxy Surveys: Observing the Universe in H-alpha emission with new generation instruments

The H-alpha line emission is an important probe for a number of fundamental quantities in galaxies, including their number density, star formation rate (SFR) and overall gas content. A new generation of low-resolution intensity mapping probes, e.g. SPHEREx and CDIM, will observe galaxies in H-alpha emission over a large fraction of the sky from the local Universe till a redshift of z ~ 6 to 10, respectively. This will also be the target line for observations by the high-resolution Euclid and WFIRST instruments in the z ~ 0.7 - 2 redshift range. In this paper, we estimate the intensity and power spectra of the H-alpha line in the z ~ 0 - 5 redshift range using observed line luminosity functions (LFs), when possible, and simulations, otherwise. We estimate the significance of our predictions by accounting for the modelling uncertainties (e.g. SFR, extinction, etc.) and observational contamination. We find that Intensity Mapping (IM) surveys can make a statistical detection of the full H-alpha emission between z ~ 0.8 - 5. Moreover, we find that the high-frequency resolution and the sensitivity of the planned CDIM surveys allow for the separation of H-alpha emission from several interloping lines. We explore ways to use the combination of these line intensities to probe galaxy properties. As expected, our study indicates that galaxy surveys will only detect bright galaxies that contribute up to a few percent of the overall H-alpha intensity. However, these surveys will provide important constraints on the high end of the H-alpha LF and put strong constraints on the AGN LF.Comment: Submitted to MNRA

Cosmology with intensity mapping techniques using atomic and molecular lines

We present a systematic study of the intensity mapping technique using updated models for the different emission lines from galaxies and identify which ones are more promising for cosmological studies of the post reionization epoch. We consider the emission of ${\rm Ly\alpha}$, ${\rm H\alpha}$, H$\beta$, optical and infrared oxygen lines, nitrogen lines, CII and the CO rotational lines. We then identify that ${\rm Ly\alpha}$, ${\rm H\alpha}$, OII, CII and the lowest rotational CO lines are the best candidates to be used as IM probes. These lines form a complementary set of probes of the galaxies emission spectra. We then use reasonable experimental setups from current, planned or proposed experiments to access the detectability of the power spectrum of each emission line. Intensity mapping of ${\rm Ly\alpha}$ emission from $z=2$ to 3 will be possible in the near future with HETDEX, while far-infrared lines require new dedicated experiments. We also show that the proposed SPHEREx satellite can use OII and ${\rm H\alpha}$ IM to study the large-scale distribution of matter in intermediate redshifts of 1 to 4. We found that submilimeter experiments with bolometers can have similar performances at intermediate redshifts using CII and CO(3-2).Comment: 18 pages, 21 figures, 5 tables, published in MNRAS, typos correcte

Growth effects of education with the extreme bounds analysis: some evidence from Asia

This paper uses the Extreme Bounds Analysis (EBA) to find robust and permanent growth effects of education by using enrolment ratios and its components in a panel of Asian countries. It is found that male and female primary and secondary enrolment ratios have robust but small permanent growth effects. However, the growth effects of male and female tertiary enrolment ratios are fragile and insignificant. In contrast to the existing estimates in the literature, which do not distinguish between the transitory and permanent growth effects, our estimated permanent growth effects are small but significant.Education and growth, Solow Growth Model, Extreme bounds analysis and Total factor productivity.

CMB Neutrino Mass Bounds and Reionization

Current cosmic microwave background (CMB) bounds on the sum of the neutrino masses assume a sudden reionization scenario described by a single parameter that determines the onset of reionization. We investigate the bounds on the neutrino mass in a more general reionization scenario based on a principal component approach. We found the constraint on the sum of the neutrino masses from CMB data can be relaxed by a $\sim$40% in a generalized reionization scenario. Moreover, the amplitude of the r.m.s. mass fluctuations $\sigma_8$ is also considerably lower providing a better consistency with a low amplitude of the Sunyaev-Zel'dovich signal

The Born and Lens-Lens Corrections to Weak Gravitational Lensing Angular Power Spectra

We revisit the estimation of higher order corrections to the angular power spectra of weak gravitational lensing. Extending a previous calculation of Cooray and Hu, we find two additional terms to the fourth order in potential perturbations of large-scale structure corresponding to corrections associated with the Born approximation and the neglect of line-of-sight coupling of two foreground lenses in the standard first order result. These terms alter the convergence ($\kappa\kappa$), the lensing shear E-mode ($\epsilon\epsilon$), and their cross-correlation ($\kappa\epsilon$) power spectra on large angular scales, but leave the power spectra of the lensing shear B-mode ($\beta\beta$) and rotational ($\omega\omega$) component unchanged as compared to previous estimates. The new terms complete the calculation of corrections to weak lensing angular power spectra associated with both the Born approximation and the lens-lens coupling to an order in which the contributions are most significant. Taking these features together, we find that these corrections are unimportant for any weak lensing survey, including for a full sky survey limited by cosmic variance.Comment: Added references, minor changes to text. 9 pages, 2 figure

An Overview of Real Interest Rate Interdependence Among the G7 Nations

We examine the interdependence of G7 90 day treasury bills on monthly data over the period 1970(1) to 2003(12). We find evidence for the presence of RIP among G7 treasury bill rates and on this evidence accept the hypothesis of a high degree of interdependence among G7 capital markets. We apply the time plot of a recursively estimated trace statistic to test for an increasing degree of integration and find little if any evidence of cointegration in the mid 1970s but interdependence increased markedly after the 1980 recession and again following the 1990 recession. From this time RIP appears to hold. A β parameter inconstancy is evident prior to mid 1979, however, the cointegration β parameters are constant over the period 1979(6) to 2003(12). The implications are explained and further research is indicated

Cross-Correlation Studies between CMB Temperature Anisotropies and 21 cm Fluctuations

During the transition from a neutral to a fully reionized universe, scattering of cosmic microwave background (CMB) photons via free-electrons leads to a new anisotropy contribution to the temperature distribution. If the reionization process is inhomogeneous and patchy, the era of reionization is also visible via brightness temperature fluctuations in the redshifted 21 cm line emission from neutral Hydrogen. Since regions containing electrons and neutral Hydrogen are expected to trace the same underlying density field, the two are (anti) correlated and this is expected to be reflected in the anisotropy maps via a correlation between arcminute-scale CMB temperature and the 21 cm background. In terms of the angular cross-power spectrum, unfortunately, this correlation is insignificant due to a geometric cancellation associated with second order CMB anisotropies. The same cross-correlation between ionized and neutral regions, however, can be studied using a bispectrum involving large scale velocity field of ionized regions from the Doppler effect, arcminute scale CMB anisotropies during reionization, and the 21 cm background. While the geometric cancellation is partly avoided, the signal-to-noise ratio related to this bispectrum is reduced due to the large cosmic variance related to velocity fluctuations traced by the Doppler effect. Unless the velocity field during reionization can be independently established, it is unlikely that the correlation information related to the relative distribution of ionized electrons and regions containing neutral Hydrogen can be obtained with a combined study involving CMB and 21 cm fluctuations.Comment: 10 pages, 3 figure

Scintillation Caustics in Planetary Occultation Light Curves

We revisit the GSC5249-01240 light curve obtained during its occultation by Saturn's North polar region. In addition to refractive scintillations, the power spectrum of intensity fluctuations shows an enhancement of power between refractive and diffractive regimes. We identify this excess power as due to high amplitude spikes in the light curve and suggest that these spikes are due to caustics associated with ray crossing situations. The flux variation in individual spikes follows the expected caustic behavior, including diffraction fringes which we have observed for the first time in a planetary occultation light curve. The presence of caustics in scintillation light curves require an inner scale cut off to the power spectrum of underlying density fluctuations associated with turbulence. Another possibility is the presence of gravity waves in the atmosphere. While occultation light curves previously showed the existence of refractive scintillations, a combination of small projected stellar size and a low relative velocity during the event have allowed us to identify caustics in this occultation. This has led us to re-examine previous data sets, in which we have also found likely examples of caustics.Comment: 4 pages, 3 figures; ApJL submitte