A generalized phase space approach for solving quantum spin dynamics

Numerical techniques to efficiently model out-of-equilibrium dynamics in interacting quantum many-body systems are key for advancing our capability to harness and understand complex quantum matter. Here we propose a new numerical approach which we refer to as GDTWA. It is based on a discrete semi-classical phase-space sampling and allows to investigate quantum dynamics in lattice spin systems with arbitrary $S\geq 1/2$. We show that the GDTWA can accurately simulate dynamics of large ensembles in arbitrary dimensions. We apply it for $S>1/2$ spin-models with dipolar long-range interactions, a scenario arising in recent experiments with magnetic atoms. We show that the method can capture beyond mean-field effects, not only at short times, but it also correctly reproduces long time quantum-thermalization dynamics. We benchmark the method with exact diagonalization in small systems, with perturbation theory for short times, and with analytical predictions made for closed system which feature quantum-thermalization at long times. By computing the Renyi entropy, currently an experimentally accessible quantifier of entanglement, we reveal that large $S$ systems can feature larger entanglement than corresponding $S=1/2$ systems. Our analyses demonstrate that the GDTWA can be a powerful tool for modeling complex spin dynamics in regimes where other state-of-the art numerical methods fail

ECONOMIC IMPACTS OF CALIFORNIA'S GOLF COURSE FACILITIES IN 2000

People spent $4.350 billion at California golf course facilities in 2000. The total sales, income, and tax impacts on the state economy were$7.872 billion, $4.546 billion, and$1.370 billion in 2000. Direct sales of $4.251 billion directly supported 62,173 jobs, and , through indirect and induced sales impacts, an additional 37,609 jobs.Land Economics/Use,

A GIS-Multicriteria Approach to Analyzing Noise and Visual Impacts of Wind Farms

Land-use conflicts in facility siting can trigger public opposition in communities. A negative public perception, such as the Not-in-my-backyard (NIMBY) attitude, is a planning issue that is strongly associated with some types of siting decisions. After the Feed-in-Tariff (FIT) program through the Green Energy Act was introduced in Ontario in 2009, a large number of wind farm developments were proposed and implemented. Public concerns regarding the noise and aesthetic impacts of wind turbines have created public resistance and caused project delays. More importantly, the wind farm siting decision making process is a top-down process, which overrides the power of municipalities and ignores public concerns towards wind farms. In this thesis, a Geographic Information System (GIS)-based multi-criteria decision analysis (MCDA) siting approach has been developed, which is capable of representing the potential noise and visual impacts caused by wind turbines in a wind farm siting process. After identifying a sample of feasible sites in Southern Ontario, the noise and visual impact assessment approaches were applied to estimate the affected-population by wind farm sites. The changes of suitability levels within each feasible site can be determined after the integration of noise and visual criteria with the common siting criteria, which include physical, environmental, planning and economic factors. This siting approach is generalizable, which means it can be applied to other facility developments that have potential noise and visual impacts to the public. The results illustrate the spatial changes of suitability level before and after introducing the noise and visual criteria into the siting process. Planners and decision makers could potentially apply this siting approach to address public concerns in the future wind farm siting decisions

MOVING BEYOND “THEORY T”: THE CASE OF QUANTUM FIELD THEORY

A standard approach towards interpreting physical theories proceeds by first identifying the theory with a set of mathematical objects, where such objects are defined according to mathematicians’ standards of rigor. In making this identification, philosophers rule out the relevance of many inferential methods that physicists use, as these often do not meet mathematicians’ standards of rigor. Philosophers thus sanitize physical theories of all math- ematically messy or ambiguous parts before interpreting them. My dissertation argues against this sanitized approach towards interpreting theories using the example of quantum field theory (QFT). When we look at the details of QFT, we find that the mathematical objects it requires differ according to the specific systems the theory is being applied to in ways that advocates of the sanitized approach do not anticipate. Furthermore, the mathematical objects required for successful application are still being developed in some applicational contexts, so it would be unwise to determine in advance which objects constitute the theory. During this ongoing developmental process, physicists interpret the mathematics using strategies that violate the standards of pure mathematics. In contrast to the sanitized approach, these strategies are more sensitive to the ways in which the mathematics required for the relevant contexts is still under development. I argue that these strategies are not merely instrumental. They suggest alternative approaches to interpretation that philosophers should take into account