871 research outputs found
Continuous variable quantum computation of the model in 1+1 dimensions
We formulate the non-linear sigma model in 1+1 dimensions as a limit
of a three-component scalar field theory restricted to the unit sphere in the
large squeezing limit. This allows us to describe the model in terms of the
continuous variable (CV) approach to quantum computing. We construct the ground
state and excited states using the coupled-cluster Ansatz and find excellent
agreement with the exact diagonalization results for a small number of lattice
sites. We then present the simulation protocol for the time evolution of the
model using CV gates and obtain numerical results using a photonic quantum
simulator. We expect that the methods developed in this work will be useful for
exploring interesting dynamics for a wide class of sigma models and gauge
theories, as well as for simulating scattering events on quantum hardware in
the coming decades.Comment: 28 pages, 16 figure
Toward quantum computations of the model using qumodes
We express the discrete 1+1-dimensional non-linear sigma model
(NLM) in a form well-suited for the continuous variable approach to
quantum computing. Within the Schwinger boson formulation, we need two qumodes
(quantum-mechanical oscillators) at each lattice site. We envision that it
might be possible to reach the scaling regime of this model and observe
asymptotic freedom on near-term photonic quantum devices in the coming decade.Comment: Proceedings for the 40th International Symposium on Lattice Field
Theory (31 July - 4 August 2023) at Fermilab. 8 pages. Comments welcome
The L.E.A.D. Project: Leading educational achievement through dialogue 2010
The L.E.A.D. Project: Leading Educational Achievement Through Dialogue 2010 is the report of the research team from the University of Notre Dame Australia funded by the Australian Government Quality Teacher Program. It is a multi-site case study which gathered data on high performing secondary schools in the Catholic system of Western Australia The data was gathered from 9 secondary schools in the Catholic system. All Principals and Deputy Principals (Curriculum) were interviewed for the study. Focus groups of Heads of Learning were interviewed, in total 32 Heads of Learning participated. Focus groups of teachers were interviewed, in total 38 teachers participated in the interviews. Focus groups of recent past students were interviewed, in total 26 past students participated in the interviews. Focus groups of parents were interviewed, in total 28 parents participated. In addition a 21 item Likert scale survey was used to gather data from all teachers in the 9 schools in the study, a total of 447 teachers responded to the Likert scale (Appendix A)
Validation of the Work Capacity Test for Wildland Firefighters
Much of the reported Wildland Firefighter (WLFF) data use prediction equations which tend to underestimate oxygen consumption (VO2) during load carriage. As a result, the reported metabolic and oxygen consumption data values may actually be higher creating a larger gap between the US Forest Service arduous pack test (APT) and true occupational demand. The reported data regarding the energy cost upon which the APT has been based (22.5 mL/kg/min of oxygen) has overwhelmingly been tested in current WLFF with few participants. However, no studies have recently examined the current energy expenditure of men and women who want to qualify to become wildland firefighters. PURPOSE: Evaluate the aerobic intensity of the US Forest Service APT in a large population of non-wildland firefighters to determine if the APT is an accurate assessment of aerobic capacity as it relates to the current data of energy being expended by wildland firefighters. METHODS: To date, 40 active individuals have participated in this study (23±1.7 yrs; 175.4±9.9 cm, 77.3±15.2 kg), both male (n=22) and female (n=18). Subjects underwent one rest stage and two 7 minute trials on the treadmill walking at 1.8m/s, with a 1% grade with and without a pack weighing at 20.4 kg, as required by the APT. Oxygen consumption (ml/kg/min), and heart rate (HR) were measured continuously throughout each trial. A 3x1 repeated measures ANOVA was used to analyze differences between the three stages. RESULTS: Significant increases in VO2 (p \u3c 0.001), heart rate (p \u3c 0.001), and % max heart rate (p \u3c 0.001) were observed when comparing the unloaded to loaded stages. Measured values of VO2 increased from 18.9±1.7 mL/kg/min to 25.5±3.0 mL/kg/min when comparing unloaded to loaded stages. Heart rate increased from 125.8±20.3 bpm (unloaded) to 155.4±24.3 bpm (loaded), thus increasing the % max heart rate from 65.4±10.5% to 80.7±12.5%. CONCLUSION: When comparing the VO2 from previous research of WLFFs in the field, to that elicited during this study of the APT, the pack test requires a lower metabolic demand (22.5 mL/kg/min) than that of this study (25.5 mL/kg/min at 80% of max HR) and active WLFFs (27 mL/kg/min). Based on these observations, the APT does not fully elicit the aerobic capacity necessary to participate in all activities congruent with that of current WLFFs in the field
Larval survivorship and settlement of crown-of-thorns starfish (Acanthaster cf. solaris) at varying algal cell densities
The dispersal potential of crown-of-thorns starfish (CoTS) larvae is important in understanding both the initiation and spread of population outbreaks, and is fundamentally
dependent upon how long larvae can persist while still retaining the capacity to settle. This study quantified variation in larval survivorship and settlement rates for CoTS maintained at three different densities of a single-celled flagellate phytoplankton, Proteomonas sulcata (1 x 10^3, 1 x 10^4, and 1 x 10^5 cells/mL). Based on the larval starvation hypothesis, we expected that low to moderate levels of phytoplankton prey would significantly constrain both survival and settlement. CoTS larvae were successfully maintained for up to 50 days post-fertilization, but larval survival differed significantly between treatments. Survival was greatest at intermediate food levels (1 x 10^4 cells/mL), and lowest at high (1 x 10^5 cells/mL) food levels. Rates of settlement were also highest at intermediate food levels and peaked at 22 days post-fertilization. Peak settlement was delayed at low food levels, probably reflective of delayed development, but there was no evidence of accelerated development at high chlorophyll concentrations. CoTS larvae were recorded to settle 17–43 days post-fertilization, but under optimum conditions with intermediate algal cell densities, peak settlement occurred at 22 days post-fertilization. Natural fluctuations in nutrient concentrations and food availability may affect the number of CoTS that effectively settle, but seem unlikely to influence dispersal dynamics
Turbulent Comptonization in Relativistic Accretion Disks
Turbulent Comptonization, a potentially important damping and radiation
mechanism in relativistic accretion flows, is discussed. Particular emphasis is
placed on the physical basis, relative importance, and thermodynamics of
turbulent Comptonization. The effects of metal-absorption opacity on the
spectral component resulting from turbulent Comptonization is considered as
well.Comment: 4 page COSPAR conference proceeding. New discussion on
photo-ionization balance include
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