The Z/2\mathbb{Z}/2-equivariant cohomology of complex projective spaces

In this article we compute the cohomology of complex projective spaces associated to finite dimensional representations of $\mathbb{Z}/2$ graded on virtual representations of its fundamental groupoid. This fully graded theory, unlike the classical $RO(G)$-graded theory, allows for the definition of push-forward maps between projective spaces, which we also compute. In the computation we use relations and generators coming from the fully graded cohomology of the projective space of $\mathscr {U}$, the complete complex $\mathbb{Z}/2$-universe, as carried out by the first author. This work is the first step in a program for developing $\mathbb{Z}/2$-equivariant Schubert calculus.Comment: 42 pages, this is a minor update. The proof of the multiplicative additive structure has been uniformized with the rest of the paper. Typos have been correcte

Edaphic Specialization in Tropical Trees: Physiological Correlates and Responses to Reciprocal Transplantation

Recent research has documented the importance of edaphic factors in determining the habitat associations of tree species in many tropical rain forests, but the underlying mechanisms for edaphic associations are unclear. At Sepilok Forest Reserve, Sabah, Malaysian Borneo, two main soil types derived from sandstone (ridges) and alluvium (valleys) differ in nutrient and water availability and are characterized by forests differing markedly in species composition, structure, and understory light availability. We use both survey and reciprocal transplants to examine physiological adaptations to differences in light, nutrient, and water availability between these soil types, and test for the importance of resource-use efficiency in determining edaphic specialization. Photosynthetic surveys for congeneric and confamilial pairs (one species per soil type) of edaphic specialists and for generalists common to both soil types show that species specializing on sandstone derived soil had lower stomatal conductance at a given assimilation rate than those occurring on alluvial soil and also had greater instantaneous and integrated water-use efficiencies. Foliar dark respiration rates per unit photosynthesis were higher for sandstone ridge than alluvial lowland specialists. We suggest that these higher respiration rates are likely due to increases in photosynthetic enzyme concentrations to compensate for lower internal CO2 concentrations resulting from increased stomatal closure. This is supported by lower photosynthetic nitrogen-use efficiencies in the sandstone ridge specialists. Generalist species had lower water-use efficiencies than sandstone ridge specialists when growing on the drier, sandy ridgetops, but their nitrogen-use efficiencies did not differ from the species specialized to the more resource-rich alluvial valleys. We varied light environment and soil nutrient availability in a reciprocal transplant experiment involving two specialist species from each soil type. Edaphic specialist species, when grown on the soil type for which they were not specialized, were not capable of acclimatory shifts to achieve similar resource-use efficiencies as species specialized to that soil type. We conclude that divergent water-use strategies are an important mechanism underlying differences in edaphic associations and thus contributing to maintenance of high local tree species diversity in Bornean rain forests

The Jus Ad Bellum and the 1998 Initiation of the Eritrean-Ethopian War

From May 1998 to December 2000, Eritrea and Ethiopia engaged in an armed conflict that cost the lives of thousands of individuals, injured thousands more, and displaced tens of thousands of men, women, and children from their homes. In December 2000, the two sides concluded a comprehensive agreement that ended the war. Among other things, the agreement established the Eritrea-Ethiopia Claims Commission. Consisting of five arbitrators, the Commission’s mandate was to “decide through binding arbitration all claims for loss, damage or injury by one Government against the other” that were “related to the conflict” and that “resulted from violations of international humanitarian law, including the 1949 Geneva Conventions, or other violations of international law.” The two countries filed claims with the Commission in December 2001 and from that time until August 2009, the Commission issued seventeen arbitral awards and eight decisions, covering a broad array of claims, including inhumane treatment of prisoners of war and civilian internees, abuse of enemy aliens in a belligerent’s territory or in occupied territory, wrongful seizure of the enemy’s public or private property, indiscriminate battlefield conduct or aerial bombing, harassment of diplomats and seizure of diplomatic property, and many other matters. The book LITIGATING WAR: ARBITRATION OF CIVIL INJURY BY THE ERITREA-ETHIOPIA CLAIMS COMMISSION seeks to integrate in discrete chapters the Commission’s findings on key topics, with each chapter organized into sub-sections that deal with the principal elements of that topic. The guiding emphasis is not on who-filed-what claim but is instead on what kinds of violations were addressed by the Commission, what kinds of evidence were relevant in establishing or defending against such violations, what legal conclusions emerged in addressing those violations, and what levels of compensation were deemed appropriate when a violation was found.The dominant area of international law upon which claims before the Eritrea-Ethiopia Claims Commission were based was the jus in bello, or the law operating as between two belligerents after an armed conflict has arisen. One type of claim filed before the Commission, however, was quite different, in that it concerned an alleged violation of the jus ad bellum, or the law on when a state may resort to a use of military force against another state. As one of the most important norms for the international legal system, the Commission’s treatment of the jus ad bellum claim is of particular interest, and is addressed in the book’s Chapter IV on “Initiation of War.

Invertebrate Abundance at Northern Bobwhite Brood Locations in the Rolling Plains of Texas

Northern bobwhite (Colinus virginianus), a bird of significant ecological and economic importance throughout the Rolling Plains region of Texas, has experienced significant population declines. Bobwhites have been the focus of extensive research for decades but little is known about foraging ecology of adults and chicks during post-hatch. Invertebrates are a key summer diet component for chicks, and supply the necessary proteins and minerals needed to fuel rapid body development. We examined brood-foraging sites to investigate invertebrate abundance. We radiomarked 121 bobwhite hens during winter-spring 2008 and 2009 and subsequently monitored 14 broods post-hatch. We collected invertebrate samples from 34 brood points and random paired-locations using sweep nets. Samples were sorted by Order to ascertain abundance and diversity. There was no difference in total abundance, abundance of Coleoptera, Hemiptera, Orthoptera, and Order diversity between brood and random locations. Northern bobwhite hens do not appear to select foraging sites based upon invertebrate abundance in the Rolling Plains of Texas

Approaching the adiabatic timescale with machine-learning

The control and manipulation of quantum systems without excitation is challenging, due to the complexities in fully modeling such systems accurately and the difficulties in controlling these inherently fragile systems experimentally. For example, while protocols to decompress Bose-Einstein condensates (BEC) faster than the adiabatic timescale (without excitation or loss) have been well developed theoretically, experimental implementations of these protocols have yet to reach speeds faster than the adiabatic timescale. In this work, we experimentally demonstrate an alternative approach based on a machine learning algorithm which makes progress towards this goal. The algorithm is given control of the coupled decompression and transport of a metastable helium condensate, with its performance determined after each experimental iteration by measuring the excitations of the resultant BEC. After each iteration the algorithm adjusts its internal model of the system to create an improved control output for the next iteration. Given sufficient control over the decompression, the algorithm converges to a novel solution that sets the current speed record in relation to the adiabatic timescale, beating out other experimental realizations based on theoretical approaches. This method presents a feasible approach for implementing fast state preparations or transformations in other quantum systems, without requiring a solution to a theoretical model of the system. Implications for fundamental physics and cooling are discussed.Comment: 7 pages main text, 2 pages supporting informatio

The Aemulus Project III: Emulation of the Galaxy Correlation Function

Using the N-body simulations of the AEMULUS Project, we construct an emulator for the non-linear clustering of galaxies in real and redshift space. We construct our model of galaxy bias using the halo occupation framework, accounting for possible velocity bias. The model includes 15 parameters, including both cosmological and galaxy bias parameters. We demonstrate that our emulator achieves ~ 1% precision at the scales of interest, 0.1<r<10 h^{-1} Mpc, and recovers the true cosmology when tested against independent simulations. Our primary parameters of interest are related to the growth rate of structure, f, and its degenerate combination fsigma_8. Using this emulator, we show that the constraining power on these parameters monotonically increases as smaller scales are included in the analysis, all the way down to 0.1 h^{-1} Mpc. For a BOSS-like survey, the constraints on fsigma_8 from r<30 h^{-1} Mpc scales alone are more than a factor of two tighter than those from the fiducial BOSS analysis of redshift-space clustering using perturbation theory at larger scales. The combination of real- and redshift-space clustering allows us to break the degeneracy between f and sigma_8, yielding a 9% constraint on f alone for a BOSS-like analysis. The current AEMULUS simulations limit this model to surveys of massive galaxies. Future simulations will allow this framework to be extended to all galaxy target types, including emission-line galaxies.Comment: 14 pages, 8 figures, 1 table; submitted to ApJ; the project webpage is available at https://aemulusproject.github.io ; typo in Figure 7 and caption updated, results unchange

The Aemulus Project I: Numerical Simulations for Precision Cosmology

The rapidly growing statistical precision of galaxy surveys has lead to a need for ever-more precise predictions of the observables used to constrain cosmological and galaxy formation models. The primary avenue through which such predictions will be obtained is suites of numerical simulations. These simulations must span the relevant model parameter spaces, be large enough to obtain the precision demanded by upcoming data, and be thoroughly validated in order to ensure accuracy. In this paper we present one such suite of simulations, forming the basis for the AEMULUS Project, a collaboration devoted to precision emulation of galaxy survey observables. We have run a set of 75 (1.05 h^-1 Gpc)^3 simulations with mass resolution and force softening of 3.51\times 10^10 (Omega_m / 0.3) ~ h^-1 M_sun and 20 ~ h^-1 kpc respectively in 47 different wCDM cosmologies spanning the range of parameter space allowed by the combination of recent Cosmic Microwave Background, Baryon Acoustic Oscillation and Type Ia Supernovae results. We present convergence tests of several observables including spherical overdensity halo mass functions, galaxy projected correlation functions, galaxy clustering in redshift space, and matter and halo correlation functions and power spectra. We show that these statistics are converged to 1% (2%) for halos with more than 500 (200) particles respectively and scales of r>200 ~ h^-1 kpc in real space or k ~ 3 h Mpc^-1 in harmonic space for z\le 1. We find that the dominant source of uncertainty comes from varying the particle loading of the simulations. This leads to large systematic errors for statistics using halos with fewer than 200 particles and scales smaller than k ~ 4 h^-1 Mpc. We provide the halo catalogs and snapshots detailed in this work to the community at https://AemulusProject.github.io.Comment: 16 pages, 12 figures, 3 Tables Project website: https://aemulusproject.github.io