Preliminary Exam |
Events During the Week of December 1st through December 8th, 2024
Monday, December 2nd, 2024
- No events scheduled
Tuesday, December 3rd, 2024
- Investigating Potential Time Dependence in the Cosmic Ray Anisotropy
- Time: 2:00 pm - 4:00 pm
- Place: 5280 CH or
- Speaker: Perri Zilberman, Physics PhD Graduate Student
- Abstract: The cosmic ray flux has been found to be nearly isotropic on the sky, however a significant and robust anisotropy has been found by IceCube as well as a number of other experiments. This anisotropy is likely in part caused by cosmic rays interacting with the magnetic field of the heliosphere. The heliosphere is dynamic, largely due to changes in solar activity. This suggests that the Cosmic Ray Anisotropy should similarly vary in time, in step with the heliosphere, though there is not a consistent picture of how such a time variation would present itself observationally. Considering this, we present a model-independent method to test for time variation in the Cosmic Ray Anisotropy. This method is then validated using a sample of data from the IceCube Neutrino Observatory.
- Host: Albrecht Karle
Wednesday, December 4th, 2024
- Protocol for robust quantum networks
- Time: 2:00 pm - 4:00 pm
- Place: 5280 Chamberlin Hall or
- Speaker: Omar Khaled Nagib Abdelhakim Mohamed, Physics PhD Graduate Student
- Abstract: Quantum networks consist of quantum nodes (e.g., atomic qubits) connected by remote entanglement. For scalable quantum networks, it is essential to engineer interactions between remote atomic qubits. This is typically achieved through two-qubit gates between atomic qubits in cavities and flying photons. Previous schemes have been sensitive to experimental imperfections, with fidelities limited to the range of 75–80%. I propose an atom-photon CZ gate that utilizes doubly degenerate ground and excited state energy levels to mediate the atom-light interaction. The setup consists of a cavity and a Mach-Zehnder interferometer. The gate operates by converting error-inducing photons into losses, making the scheme less sensitive to errors compared to previous schemes.
I will also discuss my research progress on two additional projects. The first project proposes the use of Grover's algorithm in a cavity to efficiently prepare entangled states of many qubits. The second project is a mathematical and numerical method that enables fast simulation of open quantum systems through the use of generalized inverses. - Host: Mark Saffman
Thursday, December 5th, 2024
- No events scheduled
Friday, December 6th, 2024
- X-Ray Fluorescence Imaging of Early Print
- Time: 10:00 am - 12:00 pm
- Place: Sterling Hall, Room B343
- Speaker: Minhal Gardezi, Physics PhD Graduate Student
- Abstract: Print is one of humanity’s most impactful technologies, yet much of its origins remain unclear, particularly surrounding the earliest instances of moveable metal type print. While there is documentation of Korean printers using metal type as early as 1234, none of the metal types used for these earliest prints have been preserved and their metal compositions remain unknown. Even fewer technical details are known about the first European metal type press invented by Johannes Gutenberg in the mid 15th century, despite its major role in launching the Renaissance period in Europe by revolutionizing Western information dissemination. Working in collaboration with an interdisciplinary team of scholars, technical personnel, and scientists, my work aims to fill in the gaps in knowledge surrounding early print technology through X-ray fluorescence (XRF) imaging of early printed documents. XRF scans of around 50 early print specimens from across Korea and Europe (including an early 15th century bound Korean folio and fragments of an original 42-line Gutenberg Bible) as well as 7 pre-Gutenberg Arabic block prints revealed clear metal content only in the documents printed using metal type. Through collaboration with print scholars, I obtained and produced controlled test prints made using metal types with known alloys and nonmetal inks. XRF scans of these test prints confirmed the leaching of metals from the types into the paper. Here I will present my findings and propose XRF imaging as a compelling research technique for ascertaining whether a historical document was printed using metal type and, if so, determining the metal type alloy. My work adds valuable information to scholarly studies comparing early print technologies that aims to determine whether print may have arrived in Europe from Asia.
- Host: Uwe Bergmann
- Topological Data Analysis for Cosmology
- Time: 2:00 pm - 3:30 pm
- Place: 5310 Chamberlin
- Speaker: Jacky Yip, Physics PhD Graduate Student
- Abstract: The shape of data contains a great deal of information. We apply persistent homology, a tool in topological data analysis, to build summary statistics from the topology of the large-scale structure of the universe at late times. Employing the Quijote simulations, we perform a Fisher forecast and obtain constraints on cosmological parameters and primordial non-Gaussianity amplitudes. The result is that our topological summary is generally more informative compared with conventional 2-point and 3-point statistics, and combining the approaches allows for more constraining power due to breaking parameter degeneracies. We also demonstrate a pipeline for inference.
- Host: Gary Shiu