Events at Physics |
Events on Thursday, April 24th, 2025
- R. G. Herb Condensed Matter Seminar
- Certified randomness using a trapped-ion quantum processor
- Time: 10:00 am - 6:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Minzhao (Henry) Liu, JPMorganChase
- Abstract: While quantum computers have the potential to perform a wide range of practically important tasks beyond the capabilities of classical computers, realizing this potential remains a challenge. One application is the generation of remotely certifiably random bits, which are appealing for applications involving mutually untrusting parties. Recently, leveraging the classical hardness of random circuit sampling, 70 kbits of certifiably random bits, which are secure against a realistic adversary using best-known attacks, was generated using a remotely accessed untrusted trapped-ion quantum processor. We will discuss the experimental protocol, security analysis, conditions for success, and outlook. We also identify promising applications in areas including cryptography, differential privacy, and blockchain that may benefit from certified randomness, improving the security and fairness.
- Host: Matt Otten
- Astronomy Colloquium
- Galactic Correlates of Supermassive Black Hole Growth and Their Application
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Niel Brandt, Penn State
- Abstract: The co-evolution of supermassive black holes (SMBHs) and galaxies can be effectively constrained through sample-based analyses of the galactic correlates of long-term SMBH growth. Relevant correlates include galaxy stellar mass (M*), star formation rate (SFR), and compactness. The sample-averaged SMBH accretion rate (BHAR), which constrains long-term SMBH growth in galaxy populations of interest, is statistically measured using data from sensitive X-ray surveys including the Chandra Deep Fields, XMM-SERVS, COSMOS, and eFEDS. We have been advancing such investigations using partial-correlation analyses and complete, high-quality samples now reaching 8100 AGNs in 1.3 million galaxies, and I will briefly summarize some key findings. Specifically, (1) for the general galaxy population at z = 0.1-4, SMBH growth correlates most strongly with M*; (2) for bulge-dominated systems, a strong BHAR-SFR correlation is observed, indicating synchronized growth between SMBHs and bulges; (3) BHAR also clearly correlates with galaxy compactness among star-forming galaxies, likely due to enhanced nuclear gas density for compact galaxies. Furthermore, combining these empirical correlations with large-scale numerical simulations of galaxy evolution enables improved tracking of SMBH growth through accretion and mergers across cosmic history. This approach provides insights into the evolution of the SMBH mass function, the SMBH mass-M* scaling relation, the relative importance of accretion and mergers to overall SMBH growth, and long-lived wandering SMBHs.
- Host: Melinda Soares-Furtado