Random graphs from a block-stable class

A class of graphs is called block-stable when a graph is in the class if and only if each of its blocks is. We show that, as for trees, for most $n$-vertex graphs in such a class, each vertex is in at most $(1+o(1)) \log n / \log\log n$ blocks, and each path passes through at most $5 (n \log n)^{1/2}$ blocks. These results extend to `weakly block-stable' classes of graphs

Using SCUBA to place upper limits on arcsecond scale CMB anisotropies at 850 microns

The SCUBA instrument on the James Clerk Maxwell Telescope has already had an impact on cosmology by detecting relatively large numbers of dusty galaxies at high redshift. Apart from identifying well-detected sources, such data can also be mined for information about fainter sources and their correlations, as revealed through low level fluctuations in SCUBA maps. As a first step in this direction we analyse a small SCUBA data-set as if it were obtained from a Cosmic Microwave Background (CMB) differencing experiment. This enables us to place limits on CMB anisotropy at 850 microns. Expressed as Q_{flat}, the quadrupole expectation value for a flat power spectrum, the limit is 152 microKelvin at 95 per cent confidence, corresponding to C_0^{1/2} < 355 microKelvin for a Gaussian autocorrelation function, with a coherence angle of about 20--25 arcsec; These results could easily be reinterpretted in terms of any other fluctuating sky signal. This is currently the best limit for these scales at high frequency, and comparable to limits at similar angular scales in the radio. Even with such a modest data-set, it is possible to put a constraint on the slope of the SCUBA counts at the faint end, since even randomly distributed sources would lead to fluctuations. Future analysis of sky correlations in more extensive data-sets ought to yield detections, and hence additional information on source counts and clustering.Comment: 12 pages, 9 postscript figures, uses mn.st

Ordering Things: The Irish State Administration Database

New theoretical approaches to the state have posed challenges for the comparative analysis of the organizational features of states. The analysis of state bodies and state agencies has largely been confined to the sub-discipline of public administration, and has been resistant to the systematic classification that has made progress possible in other areas of comparative politics. This article argues that there is much to be gained by reconceptualizing state bodies in a comparative context. This paper profiles the classification system underlying the construction of the Irish State Administration Database (ISAD) (Hardiman et al., 2011). This paper sets out a new approach to conceptualizing the organizational and functional features of states. ISAD not only provides a valuable research resource for work on the Irish state, but can also provide a framework for building a comparative research agenda.