The Eternal Sunshine of the Spotless Mind

We extend the worldline measure for pocket formation in eternal inflation to allow for time-ordered bubble formation. Such a time-ordering is equivalent to imposing a preferred time-slicing on the "parent" de Sitter space. Using this measure, we describe a covariant version of the youngness paradox and show that the youngness paradox is a gauge artifact if the parent spacetime is an unbroken de Sitter space, due to the lack of an explicit time-ordering for the bubble nucleation events. We then show that one can add a "clock" to the de Sitter space, in the form of a vector field with a spontaneously broken symmetry that defines a unique timelike direction accessible to all observers. Once this is done, the existence of a preferred slicing means that the youngness paradox cannot be easily resolved. We use this to elucidate the apparent "persistence of memory" discussed recently by Garriga, Guth and Vilenkin, for inflationary universes produced by bubble nucleation.Comment: 18 pages, 5 figure

FUNCTIONAL FORM AND U.S. AGRICULTURAL PRODUCTION ELASTICITIES

Because so much agricultural policy analysis utilizes estimates of supply and demand elasticities, it is crucial to obtain the most reliable estimates possible. Where reliability cannot be adequately assessed, the sensitivity of elasticities to equally plausible a priori specifications should at least be ascertained. In this article, the sensitivity of U.S. output supply and input demand elasticities to choice of functional form. Considerable sensitivity is found to choice of functional form. Although most frequently used, the translog is generally the outlier and is the least preferred among the alternatives.Agricultural and Food Policy, Demand and Price Analysis,

Gravitational Wave Production At The End Of Inflation

We consider gravitational wave production due to parametric resonance at the end of inflation, or ``preheating''. This leads to large inhomogeneities which source a stochastic background of gravitational waves at scales inside the comoving Hubble horizon at the end of inflation. We confirm that the present amplitude of these gravitational waves need not depend on the inflationary energy scale. We analyze an explicit model where the inflationary energy scale is ~10^9 GeV, yielding a signal close to the sensitivity of Advanced LIGO and BBO. This signal highlights the possibility of a new observational ``window'' into inflationary physics, and provides significant motivation for searches for stochastic backgrounds of gravitational waves in the Hz to GHz range, with an amplitude on the order of \Omega_{gw}(k)h^2 ~ 10^-11. Finally, the strategy used in our numerical computations is applicable to the gravitational waves generated by many inhomogeneous processes in the early universe.Comment: 4 pages, Revtex, 2 figures. v2 References added, discussion clarified and improved. v3 further clarification, typo regarding source corrected. Basic results unchange

A New Mechanism for Bubble Nucleation: Classical Transitions

Given a scalar field with metastable minima, bubbles nucleate quantum mechanically. When bubbles collide, energy stored in the bubble walls is converted into kinetic energy of the field. This kinetic energy can facilitate the classical nucleation of new bubbles in minima that lie below those of the "parent" bubbles. This process is efficient and classical, and changes the dynamics and statistics of bubble formation in models with multiple vacua, relative to that derived from quantum tunneling.Comment: 4 pages, 4 figures, animations related to figures can be found at http://www.perimeterinstitute.ca/personal/jgiblin/BubbleMovies.htm

Supporting siblings of children with a special educational need or disability : an evaluation of Sibs Talk, a one‐to‐one intervention delivered by staff in mainstream schools

A group often overlooked for specific supports in schools are siblings of children with a disability, special educational needs or a serious long‐term condition (SEND). In this article we review the current sibling research and identify a lack of literature on interventions, particularly within a school context. We then present a description of Sibs Talk, an example of a new school‐based intervention to support siblings. Sibs Talk is a ten‐session, one‐to‐one intervention approach for schools to complete with Key Stage 2 children who have a brother or sister with SEND. Finally, we present an initial evaluation of the effectiveness of Sibs Talk, using a pre and post evaluation format with a sample of 55 children from 11 schools. The data presented in this evaluation indicate that Sibs Talk may have contributed to positive outcomes for participating children

Personal financial literacy among high school students in New Zealand, Japan and the United States

Personal financial literacy is becoming increasingly important in the modern world, especially for young people. In this paper we compare financial literacy of high school students in Hamilton, New Zealand, with samples from Japan and the United States. We compare not only overall financial literacy, but also literacy across five dimensions (or ‘themes’) of financial literacy, and across three cognitive levels. We find that financial literacy is poor overall in all three countries, but is substantially worse in New Zealand and the United States than in Japan. The performance is similar across themes and cognitive levels for U.S. and New Zealand students, but Japanese students perform better mostly in terms of their greater knowledge of terminology and definitions, rather than better comprehension and ability to apply their knowledge. This suggests that all three countries should work harder to develop the financial literacy of their high school students