Browsing by Subject "inflation"

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    A study of relativistic fluids with applications to cosmology: A variational approach
    (2021) Oreta, Timothy; Osano, Bob
    This thesis examines relativistic fluids. We have used the variational approach to develop tools for studying the dynamics of relativistic fluids to apply this to cosmological modelling. Studies like these go beyond the standard model in cosmology. Researchers believe that such extensions to the standard cosmological model are pivotal to resolving some of the long-standing cosmological problems. An example of such problems is the origin, growth (from quantum electromagnetic fluctuations to large-scale magnetic fields during inflation) and evolution of cosmological magnetic fields that exhibit as large-scale (cosmological) magnetic fields in late time. One other example is the coincidence problem. The standard approach in such studies is to use modelling in the form of the single-fluid formalism. As an alternative one can consider the single-fluid and multi-fluid formalisms that incorporate aspects of electrodynamics and thermodynamics, respectively in the context of the variational approach. This might help us make progress in trying to either resolve some of these problems or at least open up new ways of addressing them. In this regard, we have extended the well-known M¨ueller-Israel-Stewart (hereafter MIS) formalism to allow us to examine the effect on fluid flow in which the components of the multi-species fluids interact thermodynamically. We use the extension to the MIS theory in the context of interacting species to study the growth of dark matter and dark energy, and find that either interaction or entrainment involving dark energy and dark matter suggests a mutual relative modulation of the growth behaviour of the two densities. This may aid in resolving the coincidence problem. Our examination of inflation-generated, large-scale magnetic fields reveals a super-adiabatically evolving mode from the beginning of the radiation-dominated epoch to either much later during the epoch or probably extending far into the era of matter domination which may account for late time, large-scale magnetic fields.
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    Modelling inflation in South Africa: A multivariate cointegration analysis
    (Wiley, 2005) Fedderke, J W; Schaling, E
    We employ an expectations augmented Phillips curve framework to investigate the link between inflation, unit labour costs, the output gap, the real exchange rate and inflation expectations. Using multivariate cointegration techniques, we find evidence consistent with mark-up behaviour of output prices over unit labour costs. Most importantly, we find that the mark-up in the South African economy is much higher than in the U.S. For South Africa we find a markup of about 30 per cent: three times as high as the 10 per cent markup found for the U.S. Keywords: imperfect competitions, wage-setting, price-setting, inflation, markup, cointegration. JEL Classification: E31, E37, E50
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    Open Access
    The bank of Japan’s intervention in exchange-traded funds as an effective monetary policy tool
    (2018) Pretorius, Ramon; Biekpe, Nicholas; Sokolovski, Valeri
    Since the end of October 2010, the Bank of Japan has been pursuing a new Asset Purchase Programme, which includes, among other things, direct intervention in the domestic stock market through the purchase of exchange-traded funds. This research study evaluated the impact of the Bank of Japan’s exchange-traded fund purchase programme on market returns using an event study methodology. An investigation into a sample of 33 intervention events in the Nikkei 400 exchangetraded fund and 303 intervention events in the Nikkei 225 exchange-traded fund, found that the average abnormal one-day return is -1.36% for the Nikkei 400 exchange-traded fund and -1.39% for the Nikkei 225 exchange-traded fund, while the average abnormal five-day return is -0.63% and -1.11% for each exchange-traded fund respectively. Due to the high volatility, statistically the returns are indistinguishable from zero. However, this study presents evidence that the Bank of Japan intervenes predominantly during large decreases in the market. Hence, there is suggestive evidence that the Bank of Japan’s policy is effective at reducing market losses, but is not extensive enough to significantly increase returns.