The effect of reionization on the COBE normalization

We point out that the effect of reionization on the microwave anisotropy power spectrum is not necessarily negligible on the scales probed by COBE. It can lead to an upward shift of the COBE normalization by more than the one-sigma error quoted ignoring reionization. We provide a fitting function to incorporate reionization into the normalization of the matter power spectrum.Comment: 3 pages LaTeX file with three figures incorporated (uses mn.sty and epsf

A possible contribution to CMB anisotropies at high l from primordial voids

We present preliminary results of an analysis into the effects of primordial voids on the cosmic microwave background (CMB). We show that an inflationary bubble model of void formation predicts excess power in the CMB angular power spectrum that peaks between 2000 < l < 3000. Therefore, voids that exist on or close to the last scattering surface at the epoch of decoupling can contribute significantly to the apparent rise in power on these scales recently detected by the Cosmic Background Imager (CBI).Comment: 5 pages, 3 figures. MNRAS accepted versio

Visualising London's Suburbs

2 - 4 April 200

An inventory of undiscovered Canadian mineral resources

Unit regional value (URV) and unit regional weight are area standardized measures of the expected value and quantity, respectively, of the mineral resources of a region. Estimation and manipulation of the URV statistic is the basis of an approach to mineral resource evaluation. Estimates of the kind and value of exploitable mineral resources yet to be discovered in the provinces of Canada are used as an illustration of the procedure. The URV statistic is set within a previously developed model wherein geology, as measured by point counting geologic maps, is related to the historical record of mineral resource production of well-developed regions of the world, such as the 50 states of the U.S.A.; these may be considered the training set. The Canadian provinces are related to this training set using geological information obtained in the same way from geologic maps of the provinces. The desired predictions of yet to be discovered mineral resources in the Canadian provinces arise as a consequence. The implicit assumption is that regions of similar geology, if equally well developed, will produce similar weights and values of mineral resources

Do the suburbs exist? Discovering complexity and specificity in suburban built form

In human geography cities are routinely acknowledged as complex and dynamic built environments. This description is rarely extended to the suburbs, which are generally regarded as epiphenomena of the urbs and therefore of little intrinsic theoretical interest in themselves. This article presents a detailed critique of this widely held assumption by showing how the idea of 'the suburban' as an essentially non-problematic domain has been perpetuated from a range of contrasting disciplinary perspectives, including those that directly address suburban subject matter. The result has been that attempts to articulate the complex social possibilities of suburban space are easily caught between theories of urbanisation that are insensitive to suburban specificity and competing representations of the suburb that rarely move beyond the culturally specific to consider their generic significance. This article proposes that the development of a distinctively suburban theory would help to undermine one-dimensional approaches to the built environment by focusing on the relationship between social organisation and the dynamics of emergent built form

A multi-disciplinary perspective on the built environment: Space Syntax and cartography – the communication challenge

8-11 June 2009

Cosmic Gravitational Shear from the HST Medium Deep Survey

We present a measurement of cosmic shear on scales ranging from 10\arcsec to 2\arcmin in 347 WFPC2 images of random fields. Our result is based on shapes measured via image fitting and on a simple statistical technique; careful calibration of each step allows us to quantify our systematic uncertainties and to measure the cosmic shear down to very small angular scales. The WFPC2 images provide a robust measurement of the cosmic shear signal decreasing from $5.2$ at 10\arcsec to $2.2$ at 130\arcsec .Comment: 4 pages 2 Postscript figures, uses emulateapj.cls Astrophysical Journal Letters, December 1, 200