VictorJuiz/thesis huggingface dataset:
New quantum field theory methods for collider physics and strongly coupled systems [electronic resource]

Searching for new physics requires ever more accurate understanding and modeling of the already known Standard Model of particles. It is also important to know where to look for new physics. In this thesis we will discuss investigations that address each of the aforementioned challenges. To model the dominant QCD backgrounds of the Standard Model more accurately it is important to use exact QCD matrix elements in the parton shower modeling. We will show that a helicity dependent unitary parton shower can achieve efficient matching with exact tree-level QCD matrix elements. The second challenge of knowing where to look for new physics is a daunting task. The Standard Model is a consistent theory all the way up to the GUT scale and using naturalness (absence of fine tuning) as a guideline for where to find new physics is proving increasingly nebulous. To locate physics beyond the Standard Model, we need something that takes us out of the standard model, and this is provided by dark matter. Perturbative unitarity can place interesting bounds on the scale of new physics for any Beyond the Standard Model theory that incorporates dark matter. Using the example of the Next to Minimally Supersymmetric Standard Model (NMSSM), we will show that perturbative unitarity combined with some basic hypothesis about dark matter can tell us where the next scale of new physics could be in a reliable way. In the last part of the thesis, we will discuss how the principle of perturbative unitarity can be applied to strongly coupled systems. A strongly coupled system with conformal symmetry admits an effective description if there is a large dimension gap in the spectrum of the dilatation operator and a parameter such as 1/N that suppresses higher point connected functions. In this case, the three-point current correlation function of a strongly coupled system with conformal symmetry can be calculated from the dual weakly coupled AdS effective theory. The three-point function admits perturbative expansion in the inverse dimension gap. The contribution from the first non-renormalizable bulk operator is computed and shown to lead to a different polarization structure compared to the leading renormalizable operator. This result is used to suggest an experimental probe of the effective description of strongly coupled systems at second order phase transition through an indirect measurement of the the dimension gap.

Keywords: Physics.
Advisor: Peskin Michael Edward
Hewett JoAnne L. advisor. Thesis advisor
Senatore Leonardo
New York State of Mind: Policing Terrorism in the Empire City

What factors explain the New York Police City Department’s (NYPD) post-9/11 counterterrorism reforms? The conventional narrative suggests that New York’s counterterrorism strategy has been a direct reaction to the events of September 11th, with the NYPD adapting to address new threats and vulnerabilities. While necessary, this 9/11-centric explanation is insufficient in understanding the scope, scale, and tactics of the NYPD’s counterterrorism strategy. Instead, the evidence suggests that imprinted institutional norms and path dependence within New York policymaking shaped the Department’s response to terrorism. Dating back to the Progressive Era, New York has demonstrated a bureaucratic bias towards internalizing national priorities, resulting in reforms that are consistently at the vanguard of policing tactics.
To advance this institutional argument, this thesis will analyze three key NYPD decision- making nodes: the reformation of a dedicated Intelligence Division, a legal battle to increase the Department’s ability to gather intelligence, and the establishment of a controversial “Demographics Unit.” At all three junctures, the evidence indicates that policymaking was propelled by a bureaucratic tendency to align reforms with national priorities, effectively ‘localizing’ a federal agenda. As a city teeming with strong-willed personalities, this forward-leaning institutional norm was bolstered by a cohort of policy entrepreneurs, eager to buck traditional notions of the role of local policymaking in a federal system. These findings provide a novel understanding of the NYPD, contributing an analytic counterpart to the conventional, event-driven narrative. While September 11th was the initial catalyst for policing reforms, institutional history and organizational behavior are necessary to explain the forward-leaning character and federally inspired content of New York’s response to terrorism.

Keywords: Center for International Security and Cooperation
CISAC
Freeman Spogli Institute
FSI
Senior
Thesis
Honors
Policing
Terrorism
Counterterrorism
New York
9/11
Thesis
Advisor: Blacker Coit D.
Taubman Phillip
Ni el problema, ni el remedio (neither the problem, nor the solution) [electronic resource] : Latina immigrant mothers negotiating deficit perspectives in U.S. early childhood education

This dissertation analyzes how a group of Latina immigrant women negotiated U.S. educational ideas and cultural messages in a program called Vamos al kinder (Let's go to kindergarten). Vamos al kinder is a preschool and parent education program for three to five-year-old Spanish-speaking children and their parents in a mid-size town in Oregon. Documenting how staff and mother-participants discussed, developed, and practiced U.S. cultural messages and parent involvement strategies in the workshops brings to light the immense amount of work, care, and love they enacted for their children and community. The dissertation has three principal conclusions. First, Latino families in my study were neither the source of nor solution to their children's potential academic challenges. Second, parent education is a complex, sometimes duplicitous space for low-income parents of color, especially Latina immigrants. Finally, Vamos al kinder and community-based programs like it can provide an alternative parent educational space, through staff's creativity, cariño (affection/care) and connections to grassroots community organizing opportunities, which allow for parent leadership. Despite deficit-oriented tools they inherited from early childhood education, the staff's tenacity in emphasizing parent and family strengths demonstrated the importance of creating safe spaces for Latina immigrant women to foster interactions, discussion, and experimentation among themselves.

Keywords: Education.
Advisor: McDermott Ray (Raymond Patrick)
Valdés Guadalupe primary advisor. Thesis advisor
Gordon Leah
Jiménez Tomás R. (Tomás Roberto)
Nonlinear Spectroscopy of Rubidium and Frequency Stabilization of a 1560 nm Diode Laser

Frequency-stabilized lasers are ubiquitous tools in laser spectroscopy and optical metrology. This thesis describes precision nonlinear spectroscopy of rubidium (Rb) at 780 nm that is achieved using the second harmonic of a diode laser at 1560 nm. The frequency of the laser is then actively stabilized to Rb resonances. It will ultimately serve as a frequency reference for optical time transfer and clock comparisons of frequency standards over a free-space optical link.

Keywords:  Department of Physics
laser spectroscopy
metrology
diode laser
second harmonic generation
rubidium
Thesis
Advisor: Hollberg Leo
Lev Benjamin
Non-simple geodesics on surfaces [electronic resource]

In this thesis, we study geodesics on pairs of pants, and then generalize our results to all surfaces. We get bounds on the number of closed geodesics in a hyperbolic surface given certain upper bounds on both length and self-intersection number. Then, we study the image on a pair of pants of certain sets of complete geodesics, which have restrictions for how the self-intersection number of their subarcs grows with subarc length. We show that such sets have low Hausdorff dimension, and in some cases are nowhere dense.

Keywords: Mathematics.
Advisor: Mirzakhani Maryam primary advisor. Thesis advisor
Church Thomas (Thomas Franklin) advisor. Thesis advisor
Kerckhoff Steve advisor. Thesis advisor
Yang Tian
Non-state governance and non-state legitimacy [electronic resource]

This project reexamines the way liberal political theory normatively evaluates the legitimacy of the power of non-state actors, including non-profit organizations, for-profit corporations, and international institutions. I argue here that, when these agents participate in governance, when they have independent authority to make, change, and enforce the rules that people must live by, their power raises the same questions of legitimacy that liberal political theory, particularly theories influenced by Rawls, evaluates through a requirement of public justification. I present empirical evidence here that this type of governance is widespread, deeply important for many people's lives, and likely to continue. However, the way that this requirement of public justification is generally understood assumes it is a unified, Westphalian state whose power is being evaluated, and the standard theory therefore cannot be applied to non-state power. The reconstructive portion of this project develops revisions to the standard Rawlsian theory of political legitimacy that, while grounded in the same widely shared liberal values, allow the theory to be applied to governance by non-state actors.

Keywords: Political Science.
Advisor: Ober Josiah primary advisor. Thesis advisor
Cohen Joshua
McQueen Alison advisor. Thesis advisor
Reich Rob advisor. Thesis advisor
Novel nanoscale photoelectron and X-ray sources [electronic resource]

We report a new optical near-field transducer comprised of a metallic nano-antenna extending from the ridge of a C-shaped metallic nano-aperture. Finite-difference time domain simulations predict that the C-aperture nano-tip (CAN-Tip) provides high intensity (650x), high optical resolution (~ [lambda]/60), and background-free near-field illumination at a wavelength of 980 nm. The CAN-Tip has an aperture resonance and tip antenna resonance which may be tuned independently, so the structure can be made resonant at ultraviolet wavelengths without being unduly small, which can be an ideal nano-optical source for the nano-photoelectron source. In the second part, we report a novel design for and first experimental demonstration of an array of nm-scale, controllable, photoelectron sources using helium ion beam milled 20 nm C-apertures. The apertures were designed and fabricated to resonate at 257 nm and coating with a thin-film photocathode while maintaining photonic resonance. We obtained beams of ~240 pA from each source with estimated emission areas of only 79.2 nm2 (1/e2). Such sources are badly needed for high throughput electron beam lithography and inspection. With far-field projection (> mm) of sub-20 nm photoelectron beams, applications open up in bio imaging, sensing, nano-metrology, and data storage. Lastly we apply the same unity magnification system to build a 3D differential phase contrast X-ray imaging system for identification of explosive materials in luggage. We aim to utilize an optically patterned photoelectron-excited X-ray source to circumvent difficulties of fabrication and power efficiency encountered when relying on conventional X-ray sources. I discuss how electron bombardment activated color centers provide a more efficient way to excite photoelectrons with lower photon energies.

Keywords: Materials Science and Engineering.
Advisor: Brongersma Mark L. primary advisor. Thesis advisor
Hesselink Lambertus primary advisor. Thesis advisor
Pease R. (R. Fabian W.) advisor. Thesis advisor
Novel phenomena driven by interactions and symmetry breaking in graphene [electronic resource]

The electronic properties of graphene are well described by a non-interacting Dirac Hamiltonian with an internal symmetry associated with spin and valley, an additional degree of freedom due to the hexagonal crystal lattice of graphene. As a result, graphene exhibits a variety of peculiar phenomena such as an anomalous quantum Hall effect or the absence of backscattering. However, this model breaks down in extremely clean samples, as interactions between electrons and with the substrate become relevant. In this work, we discuss some of the properties of graphene and boron nitride heterostructures, in particular the patterns of broken symmetry phases one can observe in these devices. First, we observe modification in the electronic band structure of graphene due to its interactions with the substrate. The sub lattice symmetry of the Dirac Hamiltonian is broken, which opens an energy gap at charge neutrality, in addition to superlattice Dirac points due to the moire pattern that graphene forms on boron nitride. We then describe transport at high magnetic field, in the quantum Hall regime, where Coulomb interactions yield spin and valley quantum Hall ferromagnetic phases, with polarized one dimensional states propagating along the edges of the device. Using dual-gated device geometries, we can address the transport properties of these edge states and in particular how they equilibrate, depending on their polarization (or absence thereof). At even higher fields, new collective ground states emerge in the fractional quantum Hall regime. In extremely clean samples we observe a plethora of fractional quantum Hall states, described by the composite fermion theory, with unexpected patterns of stability and spin polarizations. Observing these electronic phenomena requires an outstanding device quality with carrier mobility exceeding one million cm2/Vs. We describe in this work the fabrication and characterization methods that allow us to control the quality of graphene/boron nitride, as well as novel device geometries allowing for high quality bipolar transport in graphene.

Keywords: Applied Physics.
Advisor: Goldhaber-Gordon David
Kapitulnik Aharon primary advisor. Thesis advisor
Hwang Harold Yoonsung
Novel solar cell designs based on atomic layer deposition [electronic resource]

With the effects of pollution and global warming playing a larger and larger role in today's world, the case for the development of clean photovoltaic technologies to replace the dirty fuels that we have relied on since nearly the beginning of the Industrial Revolution is a straightforward one. Despite the recent inroads that solar energy has made into the electricity generation markets, there are still no existing technologies that can compete with coal, oil and natural gas from an economic perspective without significant government subsidies. Moreover, the vicious competition in the photovoltaic space has resulted in large solar panel price drops but primarily at the expense of profit margins leading to a mass extinction of cell manufacturers. No existing photovoltaic technology has a significant advantage and the fierce competition between numerous, equally matched adversaries has led to a fractured marketplace and has hindered the growth of the entire industry. In this work, a novel set of solar cell designs centered around the use of atomic layer deposition (ALD) is presented. The overriding goal is the drastic reduction of the installed cost while simultaneously maintaining the high performance achieved in current commercial single-junction solar cells. This is achieved through a three part approach: an ALD-enabled silicon heterojunction architecture chosen to optimize cell efficiency while taking advantage of the low cost ALD process, a technique for synthesizing thin c-Si solar cell absorber sheets that minimizes silicon material cost and reduces the cell weight, and a method for texturing a silicon surface with a shaped nanocone array to enable absorption of the majority of incident light while also eliminating the need for sun-tracking and associated installation costs. Each of the three primary innovations is discussed in detail as is their synthesis into final optimized devices that exhibit overall conversion efficiencies in excess of 22%. With the performance of this architecture nearly matching that of champion commercial cells, it presents a promising new approach with the potential to usher in the next generation of low-cost, high-efficiency photovoltaics.

Keywords: Mechanical Engineering.
Advisor: Prinz F. B. primary advisor. Thesis advisor
McGehee Michael
Miller D. A. B. advisor. Thesis advisor
Nudging drivers [electronic resource] : sensing, smartphone apps and incentives

Societal networks, such as electricity, healthcare and transportation networks, are constructs built around the resources that we consume on a daily basis. Problems surrounding societal networks come from the scarcity and wastage of these resources. These problems can be difficult to solve due to their distributed nature: while the cost of the problem to each network participant is small, the aggregate cost to society can be enormous. Peak demand further complicates the problems: the cost of a resource can be non-linear, and increases dramatically as the resource load increases, affecting all network participants. Two categories of solutions for these problems are capacity addition and demand management. Neither solution is perfect -- capacity addition can be ineffective as demand often increases to fill extra capacity; demand management schemes, often implemented using using charges, can run into public and political reresistance. Incentive programs present a complementary approach for demand management. Instead of charging, incentives are rewarded for behavior change. Incentive programs allow for positive public perception, incremental deployment and personalization, all of which are difficult with charging schemes. Concepts from nudges can be applied to the design of incentive programs; the use of accurate sensing, random rewards, interactive games, social nudging and personalized incentives can synergize to create an effective incentive program. Steptacular and INSINC are programs previously deployed by the Stanford Center for Societal Networks which demonstrate the effectiveness of nudges. Capri, the main thrust of the thesis, is an incentive program for commuters at Stanford University, seeking to reduce peak hour automobile congestion on the Stanford University campus. By incentivizing off-peak and alternative mode commutes, Capri is an effective complement to Stanford's existing transporation demand management programs. By using low-cost, high-accuracy sensing methods of RFID and smartphone geolocationing, and incorporating elements of nudging, personalization and trendjacking, Capri has been effective in shifting the commute times of a large set of users out of peak hours. The rich data generated by Capri participants allow us to quantify the effects of various program features on user performance. More generally, Capri shows that concepts of nudging are widely applicable for incentive programs in societal networks. The architecture espoused by Capri can be used to deploy incentive programs in other settings such as health networks.

Keywords: Electrical Engineering.
Advisor: Prabhakar Balaji
Rajagopal Ram advisor. Thesis advisor
Rosenblum Mendel advisor. Thesis advisor
Numerical studies of inelastic light scattering in correlated materials [electronic resource]

The mechanism of high temperature superconductivity has been a puzzle for almost three decades. With the rapid development of synchrotron light sources, photon spectroscopies such as x-ray absorption (XAS), inelastic x-ray scattering (IXS) and resonant inelastic x-ray scattering (RIXS), have shown to provide more and more useful information for the study of elementary excitations in strongly correlated ma- terials. In particular, RIXS at the Cu K-edge has been shown to be a probe of charge excitations. RIXS at the Cu L-edge in hole-doped cuprates has been shown to measure high energy collective spin excitations which persist well into the overdoped regime. We perform numerical simulations to study light scattering cross-sections using the single and multi-orbital Hubbard models. Our calculations highlight the ability to obtain spin and charge dynamical structure factors using Cu L or K-edge RIXS, respectively, and the importance of incident energy dependence (or the res- onant pro le) and the full in uence of light polarization. Our results ll in the gap between theoretical understanding and inelastic light scattering experiments on correlated materials, and further provides useful information for understanding the superconducting mechanism.

Keywords: Applied Physics.
Advisor: Devereaux Thomas Peter
Shen Zhi-Xun primary advisor. Thesis advisor
Qi Xiaoliang advisor. Thesis advisor
Objective probability and the art of judgment [electronic resource]

This dissertation argues that for many purposes, it is often useful to regard probability as objective; and, furthermore, that we can do so without any metaphysically heavyweight commitments. Those claims will be defended within three broad domains: quantum mechanics, classical statistical mechanics, and macroscopic chance events such as coin tosses. It will be explored how taking objective probability as a function of two arguments (i.e., taking it as primitively conditional) contributes to its overall usefulness. Finally, it will be discussed how objective probability can guide our actual degrees of belief. A pluralist picture will be presented in which many variants of Lewis's Principal Principle are all of some use, each with their merits and demerits.

Keywords: Philosophy.
Advisor: Ryckman Thomas primary advisor. Thesis advisor
Friedman Michael
Lawlor Krista advisor. Thesis advisor
Skyrms Brian advisor. Thesis advisor
On growth and form [electronic resource] : a bacterial perspective

Life as we know it not only requires complexity, it also necessitates organization. Without organization, the concepts of growth and form are meaningless: in order to survive and reproduce efficiently, living organisms had to evolve to overcome the physical tendency of matter to equilibrate in a disordered state. This thesis explores the interconnection between morphology and cell growth in bacteria, highlighting the importance of organization in bacterial biology. Specifically, this work describes the physical and biochemical mechanisms that specify cellular morphology in Escherichia coli and how morphology impacts development and cellular processes.

Advisor: Huang Kerwyn Casey
Fisher Daniel advisor. Thesis advisor
Quake Stephen Ronald advisor. Thesis advisor
Theriot Julie advisor. Thesis advisor
On higher q, t-Catalan numbers [electronic resource]

The purpose of this thesis is two-fold: to give a self-contained evaluation of the symmetric function version of higher , t$-Catalan numbers $SC_n^{(m)}(q, t) = \langle \nabla^m e_n, e_n \rangle$ as a summation of rational functions of $ and $ indexed by partitions, and to prove the conjecture that the combinatorial version $WC_n^{(m)}(q, t)$ and the symmetric function version $SC_n^{(m)}(q, t)$ of higher , t$-Catalan numbers are equivalent for $ up to 6, thus strengthening a result of Lee, Li, and Loehr (see~\cite[Section 5]{LLL14}) which shows the equivalence for $ up to 4.

Keywords: Mathematics.
Advisor: Vakil Ravi primary advisor. Thesis advisor
Diaconis Persi advisor. Thesis advisor
Yun Zhiwei