11,556 research outputs found
A Multi-Factor Analysis of AREIT Returns
Since 1990, the Australian Real Estate Investment Trust (AREIT) sector has experienced substantial growth and popularity. While the AREIT sector had benefit from the increased flow of funds from institutional investors during the 1997 Asian financial crisis, the recent impact of the 2008 global financial crisis has been a negative one. In this paper, we examine the sensitivities of annualised AREIT returns against a set of seven firm-specific variables and four market-wide risk variables. Balanced and unbalanced panel regressions are conducted on three sub-periods during 1990 - 2008 corresponding to the major phases in evolution of the AREIT sector. Our regression results find that size has a negative impact on returns, and this effect has been diminishing over time. Overall market risk was also found to be significant and positive only since 2003, suggesting that recently AREITs behave more like stocks and less like defensive assets. The relationship with exchange rate risk has been positive in recent years, due to more AREITs choosing to diversify internationally, particularly in the U.S. property markets. Our findings on the relationship between market-to-book ratios and AREIT returns depart from standard finance literature. In comparison to REITs in other countries, AREITs have shifted their preferences away from property-type diversification and into more specialised investment strategies. We also find contrasting evidence on the impact of international diversification, and that domestic AREITs provide better returns than internationally diversified counterparts. The relationship between returns and short term interest rates was found to be positive and significant prior to 2002, and the relationship with long-term interest rates was found to be negative and significant since 2003, suggesting that AREITs exhibit less bond-like characteristics in the past five years.AREITs, AREIT returns, Property-type diversification, International diversification, Panel regressions
Late-Time Optical Afterglow Observations with LBT and MDM
Using the 2.4m MDM and 8.4m Large Binocular Telescope, we observed nine GRB
afterglows to systematically probe the late time behaviors of afterglows
including jet breaks, flares, and supernova bumps. In particular, the LBT
observations have typical flux limits of 25-26 mag in the Sloan r' band, which
allows us to extend the temporal baseline for measuring jet breaks by another
decade in time scale. We detected four jet breaks (including a "textbook" jet
break in GRB070125) and a fifth candidate, all of which are not detectable
without deep, late time optical observations. In the other four cases, we do
not detect the jet breaks either because of contamination from the host galaxy
light, the presence of a supernova bump, or the intrinsic faintness of the
optical afterglow. This suggests that the basic picture that GRBs are
collimated is still valid and that the apparent lack of Swift jet breaks is due
to poorly sampled afterglow light curves, particularly at late times. Besides
the jet breaks, we also detected late time flares, which could attribute to
late central engine activities, and two supernova bumps.Comment: 5 pages, 5 figures, 2008 NANJING GAMMA-RAY BURST CONFERENCE. AIP
Conference Proceedings, Volume 1065, pp. 93-97 (2008), Eds. Y.F. Huang, Z.G.
Dai, B. Zhan
Observation of pinning mode in Wigner solid of 1/3 fractional quantum Hall excitations
We report the observation of a resonance in the microwave spectra of the real
diagonal conductivities of a two-dimensional electron system within a range of
~ +- .0.015 \nu=1/3\nue/3$-charged carriers .Comment: version with edits for clarity, improved Figure 3 and added referenc
Thermal Dissipation and Variability in Electrical Breakdown of Carbon Nanotube Devices
We study high-field electrical breakdown and heat dissipation from carbon
nanotube (CNT) devices on SiO2 substrates. The thermal "footprint" of a CNT
caused by van der Waals interactions with the substrate is revealed through
molecular dynamics (MD) simulations. Experiments and modeling find the
CNT-substrate thermal coupling scales proportionally to CNT diameter and
inversely with SiO2 surface roughness (~d/{\Delta}). Comparison of diffuse
mismatch modeling (DMM) and data reveals the upper limit of thermal coupling
~0.4 W/K/m per unit length at room temperature, and ~0.7 W/K/m at 600 C for the
largest diameter (3-4 nm) CNTs. We also find semiconducting CNTs can break down
prematurely, and display more breakdown variability due to dynamic shifts in
threshold voltage, which metallic CNTs are immune to; this poses a fundamental
challenge for selective electrical breakdowns in CNT electronics
Biaxial spin-nematic phase of two dimensional disordered rotor models and spin-one bosons in optical lattices
We show that the ground state of disordered rotor models with quadrupolar
interactions can exhibit biaxial nematic ordering in the disorder-averaged
sense. We present a mean-field analysis of the model and demonstrate that the
biaxial phase is stable against small quantum fluctuations. We point out the
possibility of experimental realization of such rotor models using ultracold
spin-one Bose atoms in a spin-dependent and disordered optical lattice in the
limit of a large number of atoms per site and also suggest an imaging
experiment to detect the biaxial nematicity in such systems.Comment: revtex file 7 pages, 2 figures, version published in PR
Microwave resonance of the reentrant insulating quantum Hall phases in the 1st excited Landau Level
We present measurements of the real diagonal microwave conductivity of the
reentrant insulating quantum Hall phases in the first excited Landau level at
temperatures below 50 mK. A resonance is detected around filling factor
and weaker frequency dependence is seen at and 2.28.
These measurements are consistent with the formation of a bubble phase crystal
centered around these at very low temperatures
Evidence for Two Different Solid Phases of Two Dimensional Electrons in High Magnetic Fields
We have performed RF spectroscopy on very high quality two dimensional
electron systems in the high magnetic field insulating phase, usually
associated with a Wigner solid (WS) pinned by disorder. We have found two
different resonances in the frequency dependent real diagonal conductivity
spectrum and we interpret them as coming from \textit{two} different pinned
solid phases (labeled as "WS-A" and "WS-B"). The resonance of WS-A is
observable for Landau level filling 2/9 (but absent around the
=1/5 fractional quantum Hall effect (FQHE)); it then \textit{crosses over}
for 0.18 to the different WS-B resonance which dominates the spectrum
at 0.125. Moreover, WS-A resonance is found to show dispersion with
respect to the size of transmission line, indicating that WS-A has a large
correlation length (exceeding 100 m); in contrast no such behavior
is found for WS-B. We suggest that quantum correlations such as those
responsible for FQHE may play an important role in giving rise to such
different solids.Comment: 4 pages, 3 figure
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