Popper's Experiment and Superluminal Communication

We comment on Tabesh Qureshi, "Understanding Popper's Experiment," AJP 73, 541 (June 2005), in particular on the implications of its section IV. We show, in the situation envisaged by Popper, that analysis solely with conventional non-relativistic quantum mechanics suffices to exclude the possibility of superluminal communication.Comment: Submitted to American Journal of Physic

Black Hole Entropy in M-Theory

Extremal black holes in M-theory compactification on $M\times S^1$ are microscopically represented by fivebranes wrapping $P\times S^1$, where $M$ is a Calabi-Yau threefold and $P$ is a four-cycle in $M$. Additional spacetime charges arise from momentum around the $S^1$ and expectation values for the self-dual three-form field strength in the fivebrane. The microscopic entropy of the fivebrane as a function of all the charges is determined from a two-dimensional $(0,4)$ sigma model whose target space includes the fivebrane moduli space. This entropy is compared to the macroscopic formula. Precise agreement is found for both the tree-level and one-loop expressions.Comment: 17 pages, harvma

Revolutionary Coalition Strength and Collective Failure as Determinants of Status Reallocation

This experiment investigated the effects of collective performance and coalition strength on the redistribution of status prerogatives in triads. A status hierarchy was established within triads, such that one person held higher control status and the two others held lower status. Each group performed an ambiguous, decision-making task over two trials. Collective performance (i.e., success vs failure) was manipulated via bogus feedback regarding the group’s performance, while coalition strength was manipulated by varying the extent to which the two low-status members, acting together as a revolutionary coalition, could damage the outcomes received by the high-status member. Results indicate a collective-performance main effect, with the control prerogatives of the high-status person being reduced more under failure than under success. This effect is mediated by member dissatisfaction with the group’s activities. As predicted, the results also indicate a significant Collective Performance X Coalition Strength interaction effect. Strong coalitions achieved more extensive reallocation of status prerogatives than weak ones, but this occurred only on the second trial for groups experiencing recurring failure. This effect elucidates some of the difficulties involved in mobilizing joint efforts to exercise coalition-based influence

Compact Neural Networks based on the Multiscale Entanglement Renormalization Ansatz

This paper demonstrates a method for tensorizing neural networks based upon an efficient way of approximating scale invariant quantum states, the Multi-scale Entanglement Renormalization Ansatz (MERA). We employ MERA as a replacement for the fully connected layers in a convolutional neural network and test this implementation on the CIFAR-10 and CIFAR-100 datasets. The proposed method outperforms factorization using tensor trains, providing greater compression for the same level of accuracy and greater accuracy for the same level of compression. We demonstrate MERA layers with 14000 times fewer parameters and a reduction in accuracy of less than 1% compared to the equivalent fully connected layers, scaling like O(N).Comment: 8 pages, 2 figure

The quality of group childcare settings used by 3-4 year old children in Sure Start local programme areas and the relationship with child outcomes (Research report DFE-RR068)

"Influenced by research indicating long-term benefits of early childhood programmes for disadvantaged children, the Government of the time set up Sure Start Local Programmes (SSLPs) from 1998 to reduce child poverty and social exclusion. By 2004, 524 SSLPs targeted families with children 0-4 years of age in the 20% most deprived communities. In 2005 it was decided to develop SSLPs further by turning them into children’s centres and roll out the programme nationally, ensuring that comprehensive early education and family support services are available for every community. The National Evaluation of Sure Start has been undertaking research relevant to the development of SSLPs since 2001. This part of the study focuses on 150 SSLP areas from the first four rounds of SSLPs, which are all in deprived areas." - Page iii

The Rain Forests of Home: an Atlas of People and Place

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