On a Proper Meta-Analytic Model for Correlations

Combining statistical information across studies is a standard research tool in applied psychology. The most common approach in applied psychology is the fixed effects model. The fixed-effects approach assumes that individual study characteristics such as treatment conditions, study context, or individual differences do not influence study effect sizes. That is, that the majority of the differences between the effect sizes of different studies can be explained by sampling error alone. We critique the fixed-effects methodology for correlations and propose an advancement, the random-effects model, that ameliorates problems imposed by fixed-effects models. The random-effects approach explicitly incorporates between-study differences in data analysis and provides estimates of how those study characteristics influence the relationships among constructs of interest. Because they can model the influence of study characteristics, we assert that random-effects models have advantages for psychological research. Parameter estimates of both models are compared and evidence in favor of the random-effects approach is presented

Evolution of the Fermi surface in phase fluctuating d-wave superconductors

One of the most puzzling aspects of the high $T_c$ superconductors is the appearance of Fermi arcs in the normal state of the underdoped cuprate materials. These are loci of low energy excitations covering part of the fermi surface, that suddenly appear above $T_c$ instead of the nodal quasiparticles. Based on a semiclassical theory, we argue that partial Fermi surfaces arise naturally in a d-wave superconductor that is destroyed by thermal phase fluctuations. Specifically, we show that the electron spectral function develops a square root singularity at low frequencies for wave-vectors positioned on the bare Fermi surface. We predict a temperature dependence of the arc length that can partially account for results of recent angle resolved photo emission (ARPES) experiments.Comment: Journal ref. adde

Superfluidity and dimerization in a multilayered system of fermionic polar molecules

We consider a layered system of fermionic molecules with permanent dipole moments aligned by an external field. The dipole interactions between fermions in adjacent layers are attractive and induce inter-layer pairing. Due to competition for pairing among adjacent layers, the mean-field ground state of the layered system is a dimerized superfluid, with pairing only between every-other layer. We construct an effective Ising-XY lattice model that describes the interplay between dimerization and superfluid phase fluctuations. In addition to the dimerized superfluid ground state, and high temperature normal state, at intermediate temperature, we find an unusual dimerized "pseudogap" state with only short-range phase coherence. We propose light scattering experiments to detect dimerization.Comment: 4 pages main text + 3 pages supplemental Appendices, 4 figure

Peer-to-peer solar and social rewards: evidence from a field experiment

Observability and social rewards have been demonstrated to influence the adoption of pro-social behavior in a variety of contexts. This study implements a field experiment to examine the influence of observability and social rewards in the context of a novel pro-social behavior: peer-to-peer solar. Peer-to-peer solar offers an opportunity to households who cannot have solar on their homes to access solar energy from their neighbors. However, unlike solar installations, peer-to-peer solar is an invisible form of pro-environmental behavior. We implemented a set of randomized campaigns using Facebook ads in the Massachusetts cities of Cambridge and Somerville, in partnership with a peer-to-peer company, which agreed to offer to a subsample of customers the possibility to share “green reports” online, providing shareable information about their greenness. We find that interest in peer-to-peer solar increases by up to 30% when “green reports,” which would make otherwise invisible behavior visible, are mentioned in the ad

Peer-to-peer solar and social rewards: evidence from a field experiment

Observability and social rewards have been demonstrated to influence the adoption of pro-social behavior in a variety of contexts. This study implements a field experiment to examine the influence of observability and social rewards in the context of a novel pro-social behavior: peer-to-peer solar. Peer-to-peer solar offers an opportunity to households who cannot have solar on their homes to access solar energy from their neighbors. However, unlike solar installations, peer-to-peer solar is an invisible form of pro-environmental behavior. We implemented a set of randomized campaigns using Facebook ads in the Massachusetts cities of Cambridge and Somerville, in partnership with a peer-to-peer company, which agreed to offer to a subsample of customers the possibility to share “green reports” online, providing shareable information about their greenness. We find that interest in peer-to-peer solar increases by up to 30% when “green reports,” which would make otherwise invisible behavior visible, are mentioned in the ad

Possible way out of the Hawking paradox: Erasing the information at the horizon

We show that small deviations from spherical symmetry, described by means of exact solutions to Einstein equations, provide a mechanism to "bleach" the information about the collapsing body as it falls through the aparent horizon, thereby resolving the information loss paradox. The resulting picture and its implication related to the Landauer's principle in the presence of a gravitational field, is discussed.Comment: 11 pages, Latex. Some comments added to answer to some raised questions. Typos corected. Final version, to appear in Int. J. Modern. Phys.

Designing optimal discrete-feedback thermodynamic engines

Feedback can be utilized to convert information into useful work, making it an effective tool for increasing the performance of thermodynamic engines. Using feedback reversibility as a guiding principle, we devise a method for designing optimal feedback protocols for thermodynamic engines that extract all the information gained during feedback as work. Our method is based on the observation that in a feedback-reversible process the measurement and the time-reversal of the ensuing protocol both prepare the system in the same probabilistic state. We illustrate the utility of our method with two examples of the multi-particle Szilard engine.Comment: 15 pages, 5 figures, submitted to New J. Phy