Measuring the cosmological constant with redshift surveys

It has been proposed that the cosmological constant $\Lambda$ might be measured from geometric effects on large-scale structure. A positive vacuum density leads to correlation-function contours which are squashed in the radial direction when calculated assuming a matter-dominated model. We show that this effect will be somewhat harder to detect than previous calculations have suggested: the squashing factor is likely to be $<1.3$, given realistic constraints on the matter contribution to $\Omega$. Moreover, the geometrical distortion risks being confused with the redshift-space distortions caused by the peculiar velocities associated with the growth of galaxy clustering. These depend on the density and bias parameters via the combination $\beta\equiv \Omega^{0.6}/b$, and we show that the main practical effect of a geometrical flattening factor $F$ is to simulate gravitational instability with $\beta_{\rm eff}\simeq 0.5(F-1)$. Nevertheless, with datasets of sufficient size it is possible to distinguish the two effects; we discuss in detail how this should be done. New-generation redshift surveys of galaxies and quasars are potentially capable of detecting a non-zero vacuum density, if it exists at a cosmologically interesting level.Comment: MNRAS in press. 12 pages LaTeX including Postscript figures. Uses mn.sty and epsf.st

Amino Acids in the Haemolymph of Smaller European Elm Bark Beetle Larvae, Scolytus Multistriatus (Marsham) (Coleoptera: Scolytidae)

Author Institution: Northeastern Forest Experiment Station, Forest Service, U. S. Dept. Agriculture, Delaware, Ohio 43015Nineteen amino acids and two amides were detected in the haemolymph of last-instar Scolytus multistriatus larvae by thin-layer chromatography. Glycine, arginine, glutamine, lysine, ornithine, histidine, asparagine, glutamic acid, serine, proline, alanine, valine, isoleucine, and leucine were readily detected. Taurine, phenylalanine, tyrosine, a- and B- amino butyric acid, and aspartic acid were less readily detected on some chromatograms, and at times were apparently absent in the haemolymph extract. Cysteine, cystine, and cysteic acid were not adequately separated by any of the methods tried, but their presence was confirmed through co-chromatography

Theoretical and experimental studies of the underlying processes and techniques of low pressure measurement Progress report, 1 Jun. 1966 - 31 May 1967

Construction, testing, and refining of vacuum gauges - ionization gauge cross section ratio

Lensing effect on the relative orientation between the Cosmic Microwave Background ellipticities and the distant galaxies

The low redshift structures of the Universe act as lenses in a similar way on the Cosmic Microwave Background light and on the distant galaxies (say at redshift about unity). As a consequence, the CMB temperature distortions are expected to be statistically correlated with the galaxy shear, exhibiting a non-uniform distribution of the relative angle between the CMB and the galactic ellipticities. Investigating this effect we find that its amplitude is as high as a 10% excess of alignement between CMB and the galactic ellipticities relative to the uniform distribution. The relatively high signal-to-noise ratio we found should makes possible a detection with the planned CMB data sets, provided that a galaxy survey follow up can be done on a sufficiently large area. It would provide a complementary bias-independent constraint on the cosmological parameters.Comment: 7 pages, 3 figures; uses emulateapj.sty; submitted to Ap

'We capture their comments before we leave the station': Service user involvement in the delivery of Appropriate Adult Schemes

The concept of participation is now widely accepted in healthcare and social services, but is less apparent in the delivery of services for vulnerable people who encounter the Criminal Justice System and its associated agencies (Buck et al, 2020). This article considers the extent to which children and ‘vulnerable’ adults who have been detained in police custody are currently able to actively participate in the design and delivery of Appropriate Adult Schemes. This paper draws together responses from 43 services in England and Wales concerning levels of service user engagement to ascertain the current level of participation, and to make recommendations for the future. The paper applies Forbat, et al.'s (2009) models of service user involvement to conceptualise ideological drivers which underpin the Appropriate Adult Scheme's commitment to involvement. The data reveal that while there is a genuine desire to improve service user participation, that institutional, financial, and attitudinal barriers mean that participation either does not occur or is at a very cursory level

Theoretical and experimental studies of the underlying processes and techniques of low pressure measurement Letter report, 1 Jul. 1967 - 31 May 1968

Ionization gage behavior in various gas mixtures and atmospheric composition

Lensing-Induced Structure of Submillimeter Sources: Implications for the Microwave Background

We consider the effect of lensing by galaxy clusters on the angular distribution of submillimeter wavelength objects. While lensing does not change the total flux and number counts of submillimeter sources, it can affect the number counts and fluxes of flux-limited samples. Therefore imposing a flux cut on point sources not only reduces the overall Poisson noise, but imprints the correlations between lensing clusters on the unresolved flux distribution. Using a simple model, we quantify the lensing anisotropy induced in flux-limited samples and compare this to Poisson noise. We find that while the level of induced anisotropies on the scale of the cluster angular correlation length is comparable to Poisson noise for a slowly evolving cluster model, it is negligible for more realistic models of cluster evolution. Thus the removal of point sources is not expected to induce measurable structure in the microwave or far-infrared backgrounds.Comment: 22 pages, 9 figures, accepted to Astrophysical Journa

Universality of power law correlations in gravitational clustering

We present an analysis of different sets of gravitational N-body simulations, all describing the dynamics of discrete particles with a small initial velocity dispersion. They encompass very different initial particle configurations, different numerical algorithms for the computation of the force, with or without the space expansion of cosmological models. Despite these differences we find in all cases that the non-linear clustering which results is essentially the same, with a well-defined simple power-law behaviour in the two-point correlations in the range from a few times the lower cut-off in the gravitational force to the scale at which fluctuations are of order one. We argue, presenting quantitative evidence, that this apparently universal behaviour can be understood by the domination of the small scale contribution to the gravitational force, coming initially from nearest neighbor particles.Comment: 7 pages, latex, 3 postscript figures. Revised version to be published in Europhysics Letters. Contains additional analysis showing more directly the central role of nearest neighbour interactions in the development of power-law correlation

A cosmological model in Weyl-Cartan spacetime: I. Field equations and solutions

In this first article of a series on alternative cosmological models we present an extended version of a cosmological model in Weyl-Cartan spacetime. The new model can be viewed as a generalization of a model developed earlier jointly with Tresguerres. Within this model the non-Riemannian quantities, i.e. torsion $T^{\alpha}$ and nonmetricity $Q_{\alpha \beta}$, are proportional to the Weyl 1-form. The hypermomentum $\Delta_{\alpha \beta}$ depends on our ansatz for the nonmetricity and vice versa. We derive the explicit form of the field equations for different cases and provide solutions for a broad class of parameters. We demonstrate that it is possible to construct models in which the non-Riemannian quantities die out with time. We show how our model fits into the more general framework of metric-affine gravity (MAG).Comment: 22 pages, 2 figures, uses IOP preprint styl