Semi-local Quantum Criticality and the Instability of Extremal Planar Horizons

We show that the Aretakis instability of compact extremal horizons persists in the planar case of interest to holography and discuss its connection with the emergence of "semi-local quantum criticality" in the field theory dual. In particular, the spatially localized power-law decay of this critical phase corresponds to spatially localized power-law growth of stress-energy on the horizon. For near-extremal black holes these phenomena occur transiently over times of order the inverse temperature. The boundary critical phase is characterized by an emergent temporal conformal symmetry, and the bulk instability seems to be essential to preserving the symmetry in the presence of interactions. We work primarily in the solvable example of charged scalar perturbations of five-dimensional (near-)extremal planar Reissner-Nordstr\"om anti-de Sitter spacetime and argue that the conclusions hold more generally.Comment: 23 pages. v2 contains a reference updat

SLIDES: BPI Best Practices Initiative: A Collaborative Approach to Leadership for Improving Management Practices on the Working Landscape

Presenter: Peter Zimmerman, Canadian Parks and Wilderness Society 19 slide

SLIDES: BPI Best Practices Initiative: A Collaborative Approach to Leadership for Improving Management Practices on the Working Landscape

Presenter: Peter Zimmerman, Canadian Parks and Wilderness Society 19 slide

Compressibility, hydraulic conductivity, and soil infiltration testing of tire shreds and field testing of a shredded tire horizontal drain

Laboratory testing to determine the engineering characteristics of 0.2 m to 0.4 m tire shreds was undertaken. A large scale permeameter, which allowed vertical compression of the shreds, was designed. The compressibility of the tire shreds was found. The hydraulic conductivity of the tire shreds was found at various vertical strains and flow rates. Hydraulic conductivity ranged from 1 cm/s to 8 cm/s. Hydraulic conductivity was highest at low flow rates and zero vertical strain. The hydraulic conductivity results were compared to the results of other researchers. A soil infiltration experiment was conducted to establish whether soil migration into the tire shred pore space affected the hydraulic conductivity. Glacial till and Western Iowa loess was used in the soil infiltration experiments. Soil infiltration did not greatly affect the hydraulic conductivity of the tire shreds. A 30 m long shredded tire horizontal drain was constructed and studied.;Groundwater elevations in the vicinity of the drain were monitored for a period of more than one year. The drain lowered the groundwater table elevation. The settlement of the shredded tires in the drain was surveyed on a number of dates. The tire shreds showed settlement over the long term in addition to initial settlement when backfill was placed on top of them. Two flow tests were carried out on the shredded tire drain. Water was added to the drain using a fire hose and hydrant. Water levels in the drain were measured throughout the time span of the test. The two tests were run eight months apart. Performance of the drain was not diminished over the eight month time