General relativistic neutrino transport using spectral methods

We present a new code, Lorene's Ghost (for Lorene's gravitational handling of spectral transport) developed to treat the problem of neutrino transport in supernovae with the use of spectral methods. First, we derive the expression for the nonrelativistic Liouville operator in doubly spherical coordinates (r, theta, phi, epsilon, Theta, Phi)$, and further its general relativistic counterpart. We use the 3 + 1 formalism with the conformally flat approximation for the spatial metric, to express the Liouville operator in the Eulerian frame. Our formulation does not use any approximations when dealing with the angular arguments (theta, phi, Theta, Phi), and is fully energy-dependent. This approach is implemented in a spherical shell, using either Chebyshev polynomials or Fourier series as decomposition bases. It is here restricted to simplified collision terms (isoenergetic scattering) and to the case of a static fluid. We finish this paper by presenting test results using basic configurations, including general relativistic ones in the Schwarzschild metric, in order to demonstrate the convergence properties, the conservation of particle number and correct treatment of some general-relativistic effects of our code. The use of spectral methods enables to run our test cases in a six-dimensional setting on a single processor.Comment: match published versio

Racial Formation in Perspective: Connecting Individuals, Institutions, and Power Relations

Over the past 25 years, since the publication of Omi & Winant's Racial Formation in the United States, the statement that race is socially constructed has become a truism in sociological circles. Yet many struggle to describe exactly what the claim means. This review brings together empirical literature on the social construction of race from different levels of analysis to highlight the variety of approaches to studying racial formation processes. For example, macro-level scholarship often focuses on the creation of racial categories, micro-level studies examine who comes to occupy these categories, and meso-level research captures the effects of institutional and social context. Each of these levels of analysis has yielded important contributions to our understanding of the social construction of race, yet there is little conversation across boundaries. Scholarship that bridges methodological and disciplinary divides is needed to continue to advance the racial formation perspective and demonstrate its broader relevance

Capturing more than poverty: School free and reduced-price lunch data and household income

Linking K-12 data on students and teachers to Internal Revenue Service (IRS) information allows us to answer questions that are difficult to answer using survey data or educational administrative data alone. We describe two research projects that demonstrate the importance of using linked administrative data to further research on education and inform policy discussions. In the first research project, using linked IRS income tax data to school administrative records for all 8th graders in one California public school district and all K-12th graders in Oregon public schools, we examine how well free and reduced price lunch (FRPL) enrollment captures student disadvantage. We find that FRPL categories capture relatively little variation in household income. However, FRPL captures elements of educational disadvantage that IRS-reported household income data do not. In the second research project, using data on teachers from a large California school district linked to IRS records and the Business Register, we examine what teachers do after they leave teaching. Preliminary findings suggest that many teachers leave the workforce after they leave teaching. Teachers that continue to work after leaving our school district often do so in a nearby school district, and often see a modest increase in their earnings in their new positions

Cause of Death Affects Racial Classification on Death Certificates

Recent research suggests racial classification is responsive to social stereotypes, but how this affects racial classification in national vital statistics is unknown. This study examines whether cause of death influences racial classification on death certificates. We analyze the racial classifications from a nationally representative sample of death certificates and subsequent interviews with the decedents' next of kin and find notable discrepancies between the two racial classifications by cause of death. Cirrhosis decedents are more likely to be recorded as American Indian on their death certificates, and homicide victims are more likely to be recorded as Black; these results remain net of controls for followback survey racial classification, indicating that the relationship we reveal is not simply a restatement of the fact that these causes of death are more prevalent among certain groups. Our findings suggest that seemingly non-racial characteristics, such as cause of death, affect how people are racially perceived by others and thus shape U.S. official statistics

M‐BLANK: a program for the fitting of X‐ray fluorescence spectra

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148382/1/jsy2rv5095.pd

Interrogating race: color, racial categories, and class across the Americas

We address long-standing debates on the utility of racial categories and color scales for understanding inequality in the United States and Latin America, using novel data that enable comparisons of these measures across both broad regions. In particular, we attend to the degree to which color and racial category inequality operate independently of parental socioeconomic status. We find a variety of patterns of racial category and color inequality, but that in most countries accounting for maternal education changes our coefficients by 5% or less. Overall, we argue that several posited divergences in ethnoracial stratification processes in the United States, compared with Latin America, might be overstated. We conclude that the comparison of the effects of multiple ethnoracial markers, such as color and racial categories, for the analysis of social stratification holds substantial promise for untangling the complexities of “race” across the Americas

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Duality of Orthogonal and Symplectic Matrix Integrals and Quaternionic Feynman Graphs

We present an asymptotic expansion for quaternionic self-adjoint matrix integrals. The Feynman diagrams appearing in the expansion are ordinary ribbon graphs and their non-orientable counterparts. The result exhibits a striking duality between quaternionic self-adjoint and real symmetric matrix integrals. The asymptotic expansions of these integrals are given in terms of summations over topologies of compact surfaces, both orientable and non-orientable, for all genera and an arbitrary positive number of marked points on them. We show that the Gaussian Orthogonal Ensemble (GOE) and Gaussian Symplectic Ensemble (GSE) have exactly the same graphical expansion term by term (when appropriately normalized),except that the contributions from non-orientable surfaces with odd Euler characteristic carry the opposite sign. As an application, we give a new topological proof of the known duality for correlations of characteristic polynomials. Indeed, we show that this duality is equivalent to Poincare duality of graphs drawn on a compact surface. Another application of our graphical expansion formula is a simple and simultaneous (re)derivation of the Central Limit Theorem for GOE, GUE (Gaussian Unitary Ensemble) and GSE: The three cases have exactly the same graphical limiting formula except for an overall constant that represents the type of the ensemble.Comment: 39 pages, AMS LaTeX, 49 .eps figures, references update

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