Cosmological constraint from QSO spatial power spectrum

In this paper we consider constraints on the cosmological density parameters from the spatial power spectrum of QSOs. We first review an analytic approach to the spatial power spectrum of QSOs, then we compare the result of the analytic approach with a preliminary result of the power spectrum from the two-degree Field QSO redshift (2QZ) survey. From a simple chi^2 test, we show that a finite baryon fraction better explains observation of the QSO power spectrum, which might suggest a possible detection of the baryonic oscillations in the QSO power spectrum.Comment: 3 pages, 1 figure, to appear in the proceedings of the conference "Lighthouses of the Universe: The Most Luminous Celestial Objects and Their Use for Cosmology", Garching, August 2001 (Springer-Verlag

Variety expansion and fertility rates

To investigate how fertility rates interrelate with the modern economy, we construct a simple model in which variety expansion of consumption goods reduces fertility rates. In our model, variety expansion reduces the relative price of a composite of differentiated goods compared to child- rearing costs. Thus, parents raise the expenditure share for differentiated goods and lower the number of children. We show that this model can be applied to a growth model in which economic growth progresses with variety expansion of consumption goods and fertility rates decrease with economic growth. Thus, we show a new mechanism for fertility decline, and this mechanism can be applied to a growth model.Consumerism; Fertility rates; Variety expansion; Economic growth