Risk and Real Estate Investment: An International Perspective

The literature regarding portfolio analysis for institutional real estate investors has until now largely been concerned with benefits associated with naive diversification strategies. In this paper, we discuss the prospects that institutional characteristics suggest for risk reduction in internationally diversified portfolios. The risk/return relationship of each country is affected by its own unique institutional environment and therefore there are potential benefits for investors. We argue that, given the significant differences in the institutional framework across countries, there are likely impacts on returns and that this fact deserves the attention of institutional investors.

Chiral-Odd and Spin-Dependent Quark Fragmentation Functions and their Applications

We define a number of quark fragmentation functions for spin-0, -1/2 and -1 hadrons, and classify them according to their twist, spin and chirality. As an example of their applications, we use them to analyze semi-inclusive deep-inelastic scattering on a transversely polarized nucleon.Comment: 19 pages in Plain TeX, MIT CTP #221

Enhanced non-quark-antiquark and non-glueball Nc behavior of light scalar mesons

We show that the latest and very precise dispersive data analyses require a large and very unnat- ural fine-tuning of the 1/Nc expansion at Nc = 3 if the f_0(600) and K(800) light scalar mesons are to be considered predominantly quark-antiquark states, which is not needed for light vector mesons. For this, we use scattering observables whose 1/Nc corrections are suppressed further than one power of 1/Nc for quark-antiquark or glueball states, thus enhancing contributions of other nature. This is achieved without using unitarized ChPT, but if it is used we can also show that it is not just that the coefficients of the 1/Nc expansion are unnatural, but that the expansion itself does not even follow the expected 1/Nc scaling of a glueball or a quark-antiquark meson.Comment: Discussion disfavoring a glueball interpretation added. Version published in Phys. Rev.

CMB Likelihood Functions for Beginners and Experts

Although the broad outlines of the appropriate pipeline for cosmological likelihood analysis with CMB data has been known for several years, only recently have we had to contend with the full, large-scale, computationally challenging problem involving both highly-correlated noise and extremely large datasets ($N > 1000$). In this talk we concentrate on the beginning and end of this process. First, we discuss estimating the noise covariance from the data itself in a rigorous and unbiased way; this is essentially an iterated minimum-variance mapmaking approach. We also discuss the unbiased determination of cosmological parameters from estimates of the power spectrum or experimental bandpowers.Comment: Long-delayed submission. In AIP Conference Proceedings "3K Cosmology" held in Rome, Oct 5-10, 1998, edited by Luciano Maiani, Francesco Melchiorri and Nicola Vittorio, 343-347, New York, American Institute of Physics 199

Diquarks and Exotic Spectroscopy

We propose that the recently discovered \Theta baryon is a bound state of four quarks and an antiquark, containing two highly correlated ud-pairs. If so, the \Theta baryon has positive parity, and it lies in an near-ideally mixed SU(3)_{f} \mathbf{\bar{10}}_{f} oplus \mathbf{8}_{f}. The Roper resonance and the P_{11}(1710) fit naturally into this classification. We predict an isospin 3/2 multiplet of \Xi's (S=-2) with J^{\Pi}=\half^{+} around 1750 MeV. A search for manifestly exotic \Xi^{+} and \Xi^{--} in this mass range could provide a sharp test of our proposal. We predict that charm and bottom analogues of the \Theta baryon are stable against strong decays.Comment: 5 pages, 2 figures, revtex 4, minor corrections and revisions for journal publicatio

Effect of manganese doping on the size effect of lead zirconate titanate thin films and the extrinsic nature of dead layers

We have investigated the size effect in lead zirconate titanate (PZT) thin films with a range of manganese (Mn) doping concentrations. We found that the size effect in the conventional Pt/PZT/Pt thin-film capacitors could be systematically reduced and almost completely eliminated by increasing Mn doping concentration. The interfacial layer at the electrode-film interface appears to disappear almost entirely for the PZT films with 2% Mn doping levels, confirmed by the fits using the conventional in-series capacitor model. Our work indicates that the size effect in ferroelectrics is extrinsic in nature, supporting the work by Saad et al. Other implications of our results have also been discussed. By comparing a variety of experimental studies in the literature we propose a scenario that the dead layer between PZT (or barium strontium titanate, BST) and metal electrodes such as Pt and Au might have a defective pyrochlore/fluorite structure (possibly with a small portion of ferroelectric perovskite phase).Comment: 21 pages, 6 figure

Interference Fragmentation Functions and the Nucleon's Transversity

We introduce twist-two quark interference fragmentation functions in helicity density matrix formalism and study their physical implications. We show how the nucleon's transversity distribution can be probed through the final state interaction between two mesons ($\pi^+\pi^-$, $K\bar K$, or $\pi K$) produced in the current fragmentation region in deep inelastic scattering on a transversely polarized nucleon.Comment: Final version to be published in Phys. Rev. Let

The Inclusive Semileptonic Decay Lepton Spectrum from B→Xeν‾B \to X e \overline{\nu}

In this talk, we review the QCD calculation of the lepton spectrum from inclusive semileptonic $B$ decay. We compare this prediction to that of the ACCMM model. This latter work was done in collaboration with Csaba Csaki.Comment: MIT-CTP-2333, uses LATEX. Invited Talk, Presented at WHEPP-3 Workshop in Madras,India, January, 199

Power-law weighted networks from local attachments

This letter introduces a mechanism for constructing, through a process of distributed decision-making, substrates for the study of collective dynamics on extended power-law weighted networks with both a desired scaling exponent and a fixed clustering coefficient. The analytical results show that the connectivity distribution converges to the scaling behavior often found in social and engineering systems. To illustrate the approach of the proposed framework we generate network substrates that resemble steady state properties of the empirical citation distributions of (i) publications indexed by the Institute for Scientific Information from 1981 to 1997; (ii) patents granted by the U.S. Patent and Trademark Office from 1975 to 1999; and (iii) opinions written by the Supreme Court and the cases they cite from 1754 to 2002.Comment: 18 pages, 3 figures; Proceedings of the IEEE Conference on Decision and Control and the European Control Conference, Orlando, FL, Dec. 2011; Added references; We modified the model in order to take into account extended power-law distributions which better fit to the citations data sets; Added proofs of theorems; Shorten version; Updated plo