Physics and Astronomyhttp://hdl.handle.net/10012/99492022-12-06T18:32:01Z2022-12-06T18:32:01ZSymmetries in Black Hole SpacetimesGray, Finnian Padraig Stotthttp://hdl.handle.net/10012/189352022-12-01T03:31:06Z2022-11-30T00:00:00ZSymmetries in Black Hole Spacetimes
Gray, Finnian Padraig Stott
This thesis covers the role of explicit and hidden symmetries in some selected topics on the properties and excitations of black hole spacetimes. To this end, the symmetries of classical physics in Lorentzian manifolds are reviewed.
In particular, explicit and hidden symmetries are presented from the Hamiltonian phase space perspective, and then, their role in the separability and integrability of geodesics and field equations is covered.
Next, I present some applications of hidden symmetries and separability of fields on black hole backgrounds.
Specifically this is divided into three parts.
First, the intrinsic separability of the conformal wave equation is characterized for the entire conformal class of Kerr--NUT--(Anti)-de Sitter spacetimes in all dimensions.
Second, the separability of the Maxwell and Proca equations is demonstrated two examples of spacetimes, beyond general relativity, which posses these hidden symmetries.
The results are applied in the four dimensions, to compare the unstable quasi-normal modes of the Proca field in the Kerr--Sen example to that of ordinary Kerr--Newman black holes of general relativity.
Third, I present a new class of slowly rotating black holes which can be applied to many theories beyond general relativity and are the first physically motivated example of spacetimes which posses more hidden symmetries than explicit.
Finally to conclude, I very briefly mention some possible future directions for separability of physical equations and fields in rotating black hole spacetimes.
2022-11-30T00:00:00ZCoherent interactions and thermometry in a trapped ion quantum simulatorVogliano, Anthonyhttp://hdl.handle.net/10012/189052022-10-28T02:31:02Z2022-10-27T00:00:00ZCoherent interactions and thermometry in a trapped ion quantum simulator
Vogliano, Anthony
Quantum simulators are useful tools to study exotic systems which may be otherwise
intractable for a traditional computer. In particular, the trapped-ion platform has been a
leading candidate for use in quantum simulation experiments because of its high fidelity
state-preparation and measurement operations and its all-to-all connectivity. The relative
difficulty of interacting with the long lived hyperfine states of 171Yb+ ions make them
excellent choices for encoding information as the isolation creates stability against a noisy
environment. Maintaining coherence for such a long time opens the door for complex
coherent interactions, which are a backbone of quantum simulation experiments. One of
the most critical coherent operations for a trapped-ion quantum simulator is the entangling
Molmer-Sørenson interaction.
Building up to the Molmer-Sørenson interaction requires fine control over not just the
state of the quantum register, but also the motional state of the ion. For this reason,
cooling to near the ground state of motion is crucial to obtaining high fidelity experiments.
Characterizing the temperature in such systems can prove challenging, requiring coherent
techniques.
In this thesis, I describe my work towards preparing a Molmer-Sørenson interaction
for a 171Yb+ trapped ion quantum simulator. I detail the methods used to bring-up the
coherent Raman interactions, and characterize the Doppler cooling and Continuous Side-
band Cooling (CSBC) techniques we use, their implementations on our system, and their
limitations. I characterize the temperature of our ions before and after CSBC using coher-
ent methods, showing a 46x improvement in the motional state population and confirming
that post-CSBC the ions are in the Lamb-Dicke regime. I also summarize my efforts in
constructing a future ”blade trap” system with enough precision in the alignment of the
electrodes to eventually enable efficient cooling. I show preliminary evidence that 5um
precision in blade position should be feasible.
2022-10-27T00:00:00ZEvaluation and Comparison of Two Novel Non-Platinum-Based Antitumor Agents on Pancreatic Cancer and Triple-Negative Breast CancerXu, Xiangxuanhttp://hdl.handle.net/10012/188642022-10-04T02:31:06Z2022-10-03T00:00:00ZEvaluation and Comparison of Two Novel Non-Platinum-Based Antitumor Agents on Pancreatic Cancer and Triple-Negative Breast Cancer
Xu, Xiangxuan
Cancer is one of the leading causes threatening human life. People suffering from pancreatic cancer and triple-negative breast cancer (TNBC) have particularly low survival rate among all cancer types. The novel non-platinum based antitumor agents, femtomedicine (FMD) compounds, were discovered as a new class of chemotherapeutic targeting agents to treat multiple cancers. Herein, two of the most effective FMD compounds (FMD-2Br-DAB & FMD-2I-DAB) were evaluated, based on their cytotoxicity against TNBC and pancreatic cancer cells through MTT assay, clonogenic assay, and caspase-3/7 green detection. According to the results obtained from these well-established cell-biology techniques, FMD compounds exhibit good antitumor effects in the cancer cell lines (PANC-1, BXPC-3, and MDA-MB-231), while having minimal impact on the normal cell line (GM05757), indicating FMD compounds can selectively kill TNBC and pancreatic cancer cells without being detrimental to normal cells. Furthermore, FMD-2I-DAB (compound C) shows a better efficiency than FMD-2Br-DAB (compound B), inferring that compound C could be more potent in tumor elimination. This study shows that the FMD compounds, especially for compound C, are potentially new drug candidates for effective treatment of the ‘hard-to-treat’ pancreatic cancer and TNBC.
2022-10-03T00:00:00ZTwisted Holography: The Examples of 4d and 5d Chern-Simons TheoriesZhou, Yehaohttp://hdl.handle.net/10012/188482022-09-30T02:31:27Z2022-09-29T00:00:00ZTwisted Holography: The Examples of 4d and 5d Chern-Simons Theories
Zhou, Yehao
Twisted holography is a duality between a twisted supergravity, and a twisted supersymmetric gauge theory living on the D-branes in the supergravity. The main objectives of this duality is the comparison between the algebra of observables in the bulk twisted supergravity and the algebra of observables in the boundary twisted supersymmetric gauge theory.
In this thesis, two example of the twisted holography duality are explored. The bulk theory for the first example is the 4d topological-holomorphic Chern-Simons theory, which is expected to be dual to 2d BF theory with line defects. The algebra of observables in the 2d BF theory is computed by two methods: perturbation theory (Feynman diagrams), and phase space quantization. By holography duality this algebra is expected to be isomorphic to the algebra of bulk-boundary scattering process, and the latter is computed in this thesis using perturbative method.
The bulk theory for the second example is the 5d topological-holomorphic Chern-Simons theory, which is expected to be dual to the large-N limit of a family of 1d quantum mechanics built from the ADHM quivers. The generators and relations of the large-N limit algebra of observables in the 1d quantum mechanics are studied from algebraic point view. By holography duality, this algebra is expected to be the algebra of observables on the universal line defect coupled to the 5d Chern-Simons theory, and some nontrivial relations of the latter algebra are computed in this thesis using perturbative method. The surface defects and various fusion process between line and surface defects are also explored.
2022-09-29T00:00:00Z