Jingen XiangJulia C. LeeMichael A. NowakJörn WilmsNorbert S. Schulz
We present a detailed spectral study (photoionization modelling and variability) of the “Big Dipper” 4U 1624−490 based on a Chandra -High Energy Transmission Gratings Spectrometer (HETGS) observation over the ∼ 76 ks binary orbit of 4U 1624−490 . While the continuum spectrum can be modeled using a blackbody plus power-law, a slightly better fit is obtained using a single Γ = 2.25 power-law part...
Reseña sobre José Armando Hernández Soubervielle, Sarmiento de fe, ciencia y arte. La biblioteca los jesuitas en San Luis Potosí, 1624-1767 (México: El Colegio Luis/Universidad Iberoamericana Ciudad México, 2020), 248 pp.
Journal:
:Journal of risk and financial management2021
Since the collapse of Metallgesellschaft AG due to hedging losses in 1993, energy practitioners have been concerned with ability hedge long-dated linear and non-linear oil liabilities short-dated futures options. This paper identifies a model-free non-parametric approach extrapolating prices implied volatilities. When we expand analysis implementing portfolios for or option contracts over time ...
