Perturbative entanglement entropy in nonlocal theories

Entanglement entropy in the vacuum state of local field theories exhibits an area law. However, nonlocal theories at large N and strong coupling violate this area law. In these theories, the leading divergence in the entanglement entropy is extensive for regions smaller than the effective nonlocality scale and proportional to this effective nonlocality scale for regions larger than it. This raises the question: is a volume law a generic feature of nonlocal theories, or is it only present at strong coupling and large N? This paper investigates entanglement entropy of large regions in weakly coupled nonlocal theories, to leading order in the coupling. The two theories studied are phi^4 theory on the noncommutative plane and phi^4 theory with a dipole type nonlocal modification using a fixed nonlocality scale. Both theories are found to follow an area law to first order in the coupling, hence no evidence is found for a volume law. This indicates that, perturbatively the nonlocal interactions considered are not generating sufficient entanglement at distances of the nonlocality scale to change the leading divergence, at least to first order in the coupling. An argument against volume laws at higher orders is also presented.Comment: 25 pages, 3 figures; v2 added reference

Holographic Entanglement and Poincare blocks in three dimensional flat space

We propose a covariant prescription to compute holographic entanglement entropy and Poincare blocks (Global BMS blocks) in the context of three-dimensional Einstein gravity in flat space. We first present a prescription based on worldline methods in the probe limit, inspired by recent analog calculations in AdS/CFT. Building on this construction, we propose a full extrapolate dictionary and use it to compute holographic correlators and blocks away from the probe limit.Comment: 46 pages, 6 figure

Randomization-Based Confidence Intervals for Cluster Randomized Trials

In a cluster randomized trial (CRT), groups of people are randomly assigned to different interventions. Existing parametric and semiparametric methods for CRTs rely on distributional assumptions or a large number of clusters to maintain nominal confidence interval (CI) coverage. Randomization-based inference is an alternative approach that is distribution-free and does not require a large number of clusters to be valid. Although it is well-known that a CI can be obtained by inverting a randomization test, this requires randomization testing a non-zero null hypothesis, which is challenging with non-continuous and survival outcomes. In this paper, we propose a general method for randomization-based CIs using individual-level data from a CRT. This fast and flexible approach accommodates various outcome types, can account for design features such as matching or stratification, and employs a computationally efficient algorithm. We evaluate this method\u27s performance through simulations and apply it to the Botswana Combination Prevention Project, a large HIV prevention trial with an interval-censored time-to-event outcome

Upper Body Powered Exoskeleton

The goal of this project is to build a practical and portable EMG-controlled powered exoskeleton that augments the strength of the user's bicep and tricep without hindering normal movements.University Library's Student Engagement Programhttp://deepblue.lib.umich.edu/bitstream/2027.42/122853/1/Rabideau_Kevin_FinalReport_Poster.pdfDescription of Rabideau_Kevin_FinalReport_Poster.pdf : Symposium presentation poste

Production and In Vitro Investigation of Vitamin B12-Based Bioprobes

Vitamin B12 (B12)-based bioprobes were produced and investigated in vitro for studying the B12 uptake pathway in certain cancer cell lines and their target-specific capabilities as imaging and/or contrast agents in vivo. An intrinsic factor (IF)-bound B12 conjugate (B12-ReBQBA) was produced containing rhenium(I) for in vitro analysis of the cubilin-expressing placental choriocarcinoma cell line. B12-ReBQBA has millimolar toxicity in vitro and excitation and emission wavelengths in the visible region, 488 nm and 560 nm, respectively. The rhenium metal in this bioprobe can be readily exchanged for the metastable radioactive metal technetium-99m for in vivo single-positron emission computed tomography (SPECT) scanning. A second B12-based derivative was produced, incorporating a lanthanide metal in a bifunctional macrocycle, 1,4,7,10-tetraazacyclododecane-N,N¢,N¢¢,N¢¢¢-tetraacetic acid (DOTA). Europium(III) and terbium(III) were chelated by B12-enDOTA to produce target-specific imaging agents with unique fluorescent properties. These bioprobes, which excite in the UV region, are currently being tested on breast and pancreatic cancer cell lines, T-47D and MIA PaCa-2, respectively. Future work includes sensitizing the Eu(III) and Tb(III) bioprobes so they excite and emit light in the visible region

Master of Arts

thesisOne way talkers can increase intelligibility is by producing clear speech. Though clear speech, as opposed to conversational speech (ConvS), generally increases intelligibility (known as the clear speech intelligibility benefit), not all talkers exhibit the same degree of benefit. Ferguson showed that while intelligibility increased across talkers for clear speech, when looking at individual talkers, the benefit ranged from -12.1 -33.3%. While most talkers were more intelligible during clear speech, some talkers actually became less intelligible. To explain individual differences like these, most researchers have explored acoustic, temporal, and syntactic factors. The current study probes three additional factors, ones relating to talker background: talker experience communicating with nonnative (L2) speakers, talkers' attitudes toward nonnatives, and talker experience as an L2 speaker. Twenty L2 English listeners transcribed sentences from 20 L1 English speakers as they were produced in ConvS and nonnative directed speech (NNDS; a type of clear speech). Intelligibility scores for ConvS and NNDS were compared to measure individual differences in intelligibility and to calculate the clear speech benefit for each talker. Scores were compared with the talkers' answers on a questionnaire to determine whether the variables affected the talkers' intelligibility. Results of the transcription task showed greater overall intelligibility for NNDS than ConvS; however, this was not the case for all talkers. Additionally, talkers varied widely in the benefit they provided the L2 listeners. When comparing results to the questionnaire, only talker experience as an L2 speaker was shown to affect intelligibility for L2 listeners

Higher Curvature Gravity from Entanglement in Conformal Field Theories

By generalizing different recent works to the context of higher curvature gravity, we provide a unifying framework for three related results: (i) If an asymptotically AdS spacetime computes the entanglement entropies of ball-shaped regions in a CFT using a generalized Ryu-Takayanagi formula up to second order in state deformations around the vacuum, then the spacetime satisfies the correct gravitational equations of motion up to second order around AdS; (ii) The holographic dual of entanglement entropy in higher curvature theories of gravity is given by Wald entropy plus a particular correction term involving extrinsic curvatures; (iii) CFT relative entropy is dual to gravitational canonical energy (also in higher curvature theories of gravity). Especially for the second point, our novel derivation of this previously known statement does not involve the Euclidean replica trick.Comment: 12 pages, 2 figure