39,419 research outputs found
Counting Components in the Lagrange Multiplier Formulation of Teleparallel Theories
We investigate the Lagrange multiplier formulation of teleparallel theories,
including f(T) gravity, in which the connection is not set to zero a priori and
compare it with the pure frame theory. We show explicitly that the two
formulations are equivalent, in the sense that the dynamical equations have the
same content. One consequence is that the manifestly local Lorentz invariant
f(T) theory cannot be expected to be free of pathologies, which were previously
found to plague f(T) gravity formulated in the usual pure frame approach.Comment: 6 pages, version accepted for publicatio
Introducing the At&T portfolio tours of the met
Taha Toros Arşivi, Dosya Adı: Taha Torosİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033
Modelling Volatilities and Conditional Correlations in Futures Markets with a Multivariate t Distribution
This paper considers a multivariate t version of the Gaussian dynamic conditional correlation (DCC) model proposed by Engle (2002), and suggests the use of devolatized returns computed as returns standardized by realized volatilities rather than by GARCH type volatility estimates. The
t-DCC estimation procedure is applied to a portfolio of daily returns on currency futures, government bonds and equity index futures. The results strongly reject the normal-DCC model in favour of a t-DCC specification. The t-DCC model also passes a number of VaR diagnostic tests over an evaluation sample. The estimation results suggest a general trend towards a lower level of return volatility, accompanied by a rising trend in conditional cross correlations in most markets; possibly reflecting the advent of euro in 1999 and increased interdependence of financial markets
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