7,391 research outputs found
The Specification and Influence of Asset Markets
This paper is a chapter in the forthcoming Handbook of International Economics. It surveys the literature on the specification of models of asset markets and the implications of differences in specification for the macroeconomic adjustment process. Builders of portfolio balance models have generally employed "postulated" asset demand functions, rather than deriving these directly from micro foundations. The first major sec-tion of the paper lays out a postulated general specification of asset markets and summarizes the fundamental short-run results of portfolio balance models using a very basic specification of asset markets. Then,rudimentary specifications of a balance of payments equation and goods market equilibrium conditions are supplied, so that the dynamic distribution effects of the trade account under static and rational expectations with both fixed goods prices and flexible goods prices can be analyzed.The second major section of the paper surveys and analyzes microfoundation models of asset demands using stochastic calculus. The microeconomic theory of asset demands implies some but not all of the properties of the basic specification of postulated asset demands at the macrolevel. Since the conclusions of macroeconomic analysis depend crucially on the form of asset demand functions, it is important to continue to explore the implications of micro foundations for macro specification.
Spectral Action for Robertson-Walker metrics
We use the Euler-Maclaurin formula and the Feynman-Kac formula to extend our
previous method of computation of the spectral action based on the Poisson
summation formula. We show how to compute directly the spectral action for the
general case of Robertson-Walker metrics. We check the terms of the expansion
up to a_6 against the known universal formulas of Gilkey and compute the
expansion up to a_{10} using our direct method
Further functional determinants
Functional determinants for the scalar Laplacian on spherical caps and
slices, flat balls, shells and generalised cylinders are evaluated in two,
three and four dimensions using conformal techniques. Both Dirichlet and Robin
boundary conditions are allowed for. Some effects of non-smooth boundaries are
discussed; in particular the 3-hemiball and the 3-hemishell are considered. The
edge and vertex contributions to the coefficient are examined.Comment: 25 p,JyTex,5 figs. on request
Asymptotics of relative heat traces and determinants on open surfaces of finite area
The goal of this paper is to prove that on surfaces with asymptotically cusp
ends the relative determinant of pairs of Laplace operators is well defined. We
consider a surface with cusps (M,g) and a metric h on the surface that is a
conformal transformation of the initial metric g. We prove the existence of the
relative determinant of the pair under suitable
conditions on the conformal factor. The core of the paper is the proof of the
existence of an asymptotic expansion of the relative heat trace for small
times. We find the decay of the conformal factor at infinity for which this
asymptotic expansion exists and the relative determinant is defined. Following
the paper by B. Osgood, R. Phillips and P. Sarnak about extremal of
determinants on compact surfaces, we prove Polyakov's formula for the relative
determinant and discuss the extremal problem inside a conformal class. We
discuss necessary conditions for the existence of a maximizer.Comment: This is the final version of the article before it gets published. 51
page
Wood Creek Tidal Marsh Enhancement Project Benthic Macroinvertebrate Monitoring Report 2019
The focus of this report was to monitor benthic macroinvertebrate communities on the Freshwater Farms Reserve, which underwent two phases of restoration as part of the Wood Creek Tidal Marsh Enhancement Project in 2009-2010 and 2016-2018. Objectives for the restoration activities were to increase winter rearing refugia habitat for several threatened/endangered fish species such as the tidewater goby (Eucyclogobius newberryi), Coho salmon (Oncorhynchus kisutch) and steelhead trout (Oncorhynchus mykiss). The goals of this project were to (1) sample and identify BMIs along a salinity gradient in Wood Creek; (2) assess water quality; and (3) report general trajectory of community composition over time. Results show that the abundance of benthic macroinvertebrates increased dramatically in Wood Creek in 2019 for all sampled sites when compared to previous years of monitoring data. Three taxa accounted for over 99% of the overall composition at each of the sample sites. Increased abundance of benthic macroinvertebrates may provide additional nutritional support for fish present in Wood Creek and Freshwater Creek. Overall, Freshwater Farms Reserve’s post-restoration ecological trajectory seems to be improving in relation to the goals of supporting fish refugia for threatened/endangered species
Thermodynamics, Euclidean Gravity and Kaluza-Klein Reduction
The aim of this paper is to find out a correspondence between one-loop
effective action defined by means of path integral in Euclidean gravity
and the free energy obtained by summation over the modes. The analysis is
given for quantum fields on stationary space-times of a general form. For such
problems a convenient procedure of a "Wick rotation" from Euclidean to
Lorentzian theory becomes quite non-trivial implying transition from one real
section of a complexified space-time manifold to another. We formulate
conditions under which and can be connected and establish an explicit
relation of these functionals. Our results are based on the Kaluza-Klein method
which enables one to reduce the problem on a stationary space-time to
equivalent problem on a static space-time in the presence of a gauge
connection. As a by-product, we discover relation between the asymptotic
heat-kernel coefficients of elliptic operators on a dimensional stationary
space-times and the heat-kernel coefficients of a dimensional elliptic
operators with an Abelian gauge connection.Comment: latex file, 22 page
Boundary dynamics and multiple reflection expansion for Robin boundary conditions
In the presence of a boundary interaction, Neumann boundary conditions should
be modified to contain a function S of the boundary fields: (\nabla_N +S)\phi
=0. Information on quantum boundary dynamics is then encoded in the
-dependent part of the effective action. In the present paper we extend the
multiple reflection expansion method to the Robin boundary conditions mentioned
above, and calculate the heat kernel and the effective action (i) for constant
S, (ii) to the order S^2 with an arbitrary number of tangential derivatives.
Some applications to symmetry breaking effects, tachyon condensation and brane
world are briefly discussed.Comment: latex, 22 pages, no figure
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Analyzing the Intensities of K‑Edge Transitions in X2 Molecules (X = F, Cl, Br) for Use in Ligand K‑Edge X‑ray Absorption Spectroscopy
Ligand K-edge X-ray absorption spectroscopy (XAS) is regularly used to determine the ligand contribution to metal-ligand bonds. For quantitative studies, the pre-edge transition intensities must be referenced to an intensity standard, and pre-edge intensities obtained from different ligand atoms cannot be compared without standardization due to different cross sections at each absorption edge. In this work, the intensities of the 1s → σ* transitions in F2, Cl2, and Br2 are analyzed for their use as references for ligand K-edge XAS. We show that the intensities of these transitions are equal to the intensities of the 1s → np transitions in the unbound halogens. This finding is supported by a comparison between the normalized experimental intensities for the molecules and the calculated oscillator strengths for the atoms. These results highlight the potential for these molecules to be used as intensity standards in F, Cl, and Br K-edge XAS experiments
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