Homogeneous Lorentzian manifolds of a semisimple group

We describe the structure of $d$-dimensional homogeneous Lorentzian $G$-manifolds $M=G/H$ of a semisimple Lie group $G$. Due to a result by N. Kowalsky, it is sufficient to consider the case when the group $G$ acts properly, that is the stabilizer $H$ is compact. Then any homogeneous space $G/\bar H$ with a smaller group $\bar H \subset H$ admits an invariant Lorentzian metric. A homogeneous manifold $G/H$ with a connected compact stabilizer $H$ is called a minimal admissible manifold if it admits an invariant Lorentzian metric, but no homogeneous $G$-manifold $G/\tilde H$ with a larger connected compact stabilizer $\tilde H \supset H$ admits such a metric. We give a description of minimal homogeneous Lorentzian $n$-dimensional $G$-manifolds $M = G/H$ of a simple (compact or noncompact) Lie group $G$. For $n \leq 11$, we obtain a list of all such manifolds $M$ and describe invariant Lorentzian metrics on $M$

The Common HOL Platform

The Common HOL project aims to facilitate porting source code and proofs between members of the HOL family of theorem provers. At the heart of the project is the Common HOL Platform, which defines a standard HOL theory and API that aims to be compatible with all HOL systems. So far, HOL Light and hol90 have been adapted for conformance, and HOL Zero was originally developed to conform. In this paper we provide motivation for a platform, give an overview of the Common HOL Platform's theory and API components, and show how to adapt legacy systems. We also report on the platform's successful application in the hand-translation of a few thousand lines of source code from HOL Light to HOL Zero.Comment: In Proceedings PxTP 2015, arXiv:1507.0837

Progress Toward a National Serials Data System

published or submitted for publicatio

Reparative Reasoning

Peter Ochs' notion of ‘pragmatic reading’ and his wider project of articulating a ‘logic of scripture’ are described in the first part of this article. A distinction is made between Ochs' proposals for how to read scripture and his more technical claims about how scripture itself models a ‘logic of repair’. The term ‘thirdness’ is explained in the contexts of the relations and axioms, hypotheses and communities. His readings of Hans Frei and George Lindbeck are rehearsed briefly in the second section. Their attempts to show that there is nothing ‘behind’ scripture or doctrine, to which the latter supposedly refer, are presented by Ochs as ‘pragmatic’ attempts to repair the rules which generate false oppositions in discussions of scripture and doctrine

Urban Land Reform Briefing Paper No 4: Explaining Public Interest Led Development

This is one of six briefing papers prepared by Professor David Adams of the University of Glasgow to help explain key proposals for urban land reform made in 2014 by the Scottish Government’s Land Reform Review Group (LRRG) to whom he acted as an independent adviser. This paper focuses on the LRRG’s recommendation “that the Scottish Government should encourage and support a greater emphasis on public interest led development” (see pages 128-129 of the LRRG report)

Jet Studies in STAR via Di-jet Triggered (2+1) Multi-hadron Correlations

We explore jet-medium interactions via the recently developed multi-hadron correlation or "2+1" technique. We restrict the di-jet kinematics by selecting a pair of approximately back-to-back high pT hadron triggers and study associated particles. Here we present our study of di-jet systematics comparing the measurements of associate yields and spectra in 200 GeV Au+Au and d+Au collisions in two different scenarios. We present Sum(pT) as an estimate for energy loss. First findings indicate little to no energy loss in the symmetric "2+1" scenario whereas model predictions are about 2 GeV.Comment: 4 pages, 3 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse

Urban Land Reform Briefing Paper No 1: Explaining Compulsory Sale Orders

This is one of six briefing papers prepared by Professor David Adams of the University of Glasgow to help explain key proposals for urban land reform made in 2014 by the Scottish Government’s Land Reform Review Group (LRRG) to whom he acted as an independent adviser. This paper focuses on the LRRG’s recommendations “that further mechanisms are required to address the persistent challenge of vacant and derelict land in urban areas” and “that Local Authorities should have the right to exercise a Compulsory Sale Order over an area of vacant or derelict land, and also that Community Councils, or appropriate community bodies, should have the right to request that a local authority exercises a Compulsory Sale Order” (see pages 103 and 122-124 of the LRRG report)

Elizabeth I, the Succession and Foreign Policy

Part of a special section on the reign of Queen Elizabeth I of England. The writer examines the close links between Elizabeth's ascendancy, reign, and subsequent relationships with the states of Europe. Elizabeth had a coherent foreign policy, shaped by the unusual circumstances of her reign. These were less to do with her gender--a much-exaggerated subject--than her questionable legitimacy and the coincidence that the leading members of the wider Tudor royal family were Scots. For example, until her death in 1587, Mary Stuart was the focus around which Elizabeth's foreign policy revolved. Mary was Dauphine and, after July 1559, Queen of France, and the threat of her rival claim to the English throne was the decisive motive for Elizabeth's interventions in Scotland in 1560 and France in 1562