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Time-series characteristics of UK commercial property returns: testing for multiple changes in persistence
The random-walk hypothesis, vis-à-vis asset prices , suggests that prices traded in a market cannot be predicted based on historical information. Employing unsecuritised UK commercial property returns, we analyze this hypothesis, investigating multiple changes in persistence in the series . Our results uncover multiple changes in persistence in both the aggregate and sector-specific data. We highlight some implications for academics, practitioners and regulators
Quantum-classical interactions through the path integral
I consider the case of two interacting scalar fields, \phi and \psi, and use
the path integral formalism in order to treat the first classically and the
second quantum-mechanically. I derive the Feynman rules and the resulting
equation of motion for the classical field, which should be an improvement of
the usual semi-classical procedure. As an application I use this method in
order to enforce Gauss's law as a classical equation in a non-abelian gauge
theory. I argue that the theory is renormalizable and equivalent to the usual
Yang-Mills as far as the gauge field terms are concerned. There are additional
terms in the effective action that depend on the Lagrange multiplier field
\lambda that is used to enforce the constraint. These terms and their relation
to the confining properties of the theory are discussed.Comment: 16 pages, LaTeX, 1 fig, final version to appear in PR
Quantum Fermion Hair
It is shown that the Dirac operator in the background of a magnetic
%Reissner-Nordstr\"om black hole and a Euclidean vortex possesses normalizable
zero modes in theories containing superconducting cosmic strings. One
consequence of these zero modes is the presence of a fermion condensate around
magnetically charged black holes which violates global quantum numbers.Comment: 16pp (harvmac (l)) and 2 figs.(not included
Higgs Localization in Split Fermion Models
The flavor puzzle of the Standard Model is explained in split fermion models
by having the fermions localized and separated in an extra dimension. Many of
these models assume a certain profile for the Higgs VEV, usually uniform, or
confined to a brane, without providing a dynamical realization for it. By
studying the effect of the coupling between the Higgs and the localizer fields,
we obtain these scenarios as results, rather than ansaetze. Moreover, we
discuss other profiles and show that they are phenomenologically viable.Comment: 23 pages, 16 figures, based on an MSc thesi
Persistence of inflationary shocks: Implications for West African Monetary Union Membership
Plans are far advanced to form a second monetary union, the West African Monetary Zone
(WAMZ), in Africa. While much attention is being placed on convergence criteria and
preparedness of the five aspiring member states, less attention is being placed on the extent
to which the dynamics of inflation in individual countries are (dis)similar. This paper aims to
stimulate debate on the long term sustainability of the union by examining the dynamics of
inflation within these countries. Using Fractional Integration (FI) methods, we establish that
some significant differences exist among the countries. Shocks to inflation in Sierra Leone
are non mean reverting; results for The Gambia, Ghana and Guinea-Bissau suggest some
inflation persistence, despite being mean reverting. Some policy implications are discussed
and some warnings are raised
Exploring the Dynamics of Building Supply: A Duration Model of the Development Cycle
A noticeable omission in the existing body of applied real estate research is the lack of empirical analysis of the commercial development process. We address this shortcoming by utilizing a large panel database of individual building projects that in principle allows us to follow individual projects through various stages of their development life cycle. We begin by examining the basic distributional and time series characteristics of the development cycle, and then examine how these results vary by stage of construction, property sector and geography. We then estimate unconditional transition probabilities and finally, present preliminary results from a formal, nonparametric duration model.
A Second Shell in the Fornax dSph Galaxy
In the search for tidal structure in Galactic satellite systems, we have
conducted a photometric survey over a 10 square degree area centred on the
Fornax dSph galaxy. The survey was made in two colours, and the resulting
colour-magnitude data were used as a mask to select candidate Fornax RGB stars,
thereby increasing the contrast of Fornax stars to background sources in the
outer regions. Previously, we reported the presence of a shell (age 2 Gyr)
located towards the centre of Fornax. In this contribution we reveal a second
shell, significantly larger than the first, located 1.3 degrees NW from the
centre of Fornax, outside the nominal tidal radius. Moreover, the distribution
of Fornax RGB stars reveals two lobes extending to the spatial limit of our
survey, and aligned with the minor axis and with the two shells. These results
support the hypothesis of a merger between Fornax and a gas-rich companion
approximately 2 Gyr ago.Comment: Four pages,accepted for the Publications of the Astronomical Society
of Australia. Contribution the annual ASA meeting, Brisbane 200
Gauge Group TQFT and Improved Perturbative Yang-Mills Theory
We reinterpret the Faddeev-Popov gauge-fixing procedure of Yang-Mills
theories as the definition of a topological quantum field theory for gauge
group elements depending on a background connection. This has the advantage of
relating topological gauge-fixing ambiguities to the global breaking of a
supersymmetry. The global zero modes of the Faddeev-Popov ghosts are handled in
the context of an equivariant cohomology without breaking translational
invariance. The gauge-fixing involves constant fields which play the role of
moduli and modify the behavior of Green functions at subasymptotic scales. At
the one loop level physical implications from these power corrections are gauge
invariant.Comment: 28 pages, uuencoded and compressed tar-file, LATEX+4 PS-figures, uses
psfig.sty. New appendix and some clarifying modifications, references adde
Power management and distribution considerations for a lunar base
Design philosophies and technology needs for the power management and distribution (PMAD) portion of a lunar base power system are discussed. A process is described whereby mission planners may proceed from a knowledge of the PMAD functions and mission performance requirements to a definition of design options and technology needs. Current research efforts at the NASA LRC to meet the PMAD system needs for a Lunar base are described. Based on the requirements, the lunar base PMAD is seen as best being accomplished by a utility like system, although with some additional demands including autonomous operation and scheduling and accurate, predictive modeling during the design process
Identifying Unclear Questions in Community Question Answering Websites
Thousands of complex natural language questions are submitted to community
question answering websites on a daily basis, rendering them as one of the most
important information sources these days. However, oftentimes submitted
questions are unclear and cannot be answered without further clarification
questions by expert community members. This study is the first to investigate
the complex task of classifying a question as clear or unclear, i.e., if it
requires further clarification. We construct a novel dataset and propose a
classification approach that is based on the notion of similar questions. This
approach is compared to state-of-the-art text classification baselines. Our
main finding is that the similar questions approach is a viable alternative
that can be used as a stepping stone towards the development of supportive user
interfaces for question formulation.Comment: Proceedings of the 41th European Conference on Information Retrieval
(ECIR '19), 201
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