Speakers: Graduate Students
When
Where
Lauren Willett
Young Stars and a 1D Universe
I briefly summarize my two (very different!) past research projects. The first one involved modeling the UV-optical spectra of young stars to estimate their mass accretion rates. The second one is a more theoretical cosmology-focused project, studying the clustering of matter using a 1D toy model instead of 3D. Despite being confined to a single axis, this little 1D universe can be a quite useful analog to our 3D world.
Thejus Manu
Spin Coupled Doubly Heavy Baryons and Their Magnetic Moments
Considering the fact that the arrangement of quark flavors in a baryon affects the magnetic moment predictions of baryons due to their dependence on wave functions, we investigate the magnetic moments of JP= 〖1/2〗^+doubly heavy baryons for different ordering of the constituent quarks. We implement the differential quark ordering in the SU(6) wavefunction of the heavy baryons. Furthermore, we study their magnetic moments for corresponding wavefunction configurations. We restrict our self to employ the concept of single gluon exchange interaction coupled to the spectator quarks inside a baryon to numerically predict their magnetic moments in corresponding configurations. Also, we explore the mixing of these magnetic moments among flavor-degenerate baryons for the said configurations. Finally, we compare our results with different theoretical models.
Cheng Wu
Constraints on modified gravity from the effective field theory of large-scale structure
We present a synthesis of both EFTofLSS and EFTofDE approaches to constrain parameters in modified gravity theories through comprehensive analysis of N-body simulation power spectra. We systematically compare two theoretical treatments: one incorporating the exact time dependence of modified gravity parameters, and another employing the Einstein-de Sitter approximation. While both methods demonstrate substantial projection effects, the EdS approximation provides considerably less stringent constraints on modified gravity parameters than the exact-time-dependent treatment.
Noah Bliss
Understanding the Strong Nuclear Force
The strong nuclear force binds together protons and neutrons in the nucleus of atoms, counteracting the electric repulsion between the protons. Going a level deeper reveals another layer of reality: quarks and gluons. These fundamental particles make up the nucleons as well as dozens of more exotic particles. Understanding these particles is the challenge of Quantum Chromodynamics.
Ian Busby
Correlation Between Light Curve and Spectral Behavior in Bright Gamma-Ray Bursts
On a data set of 62 bright gamma-ray bursts (GRBs) from the Fermi Space Telescope we show that single-peaked gamma-ray bursts are more likely to have a hard to soft spectral evolution. In contrast, bursts with multiple peaks do not generally demonstrate monotonic spectral behavior. When placed in the internal/external shock framework, this behavior agrees with the prompt emission from some GRBs occurring in highly dense regions of space.
Bayli Hayes
Star-forming Nuclear Clusters in Dwarf Galaxies Mimicking Active Galactic Nucleus Signatures in the Mid-infrared
Effectively finding and identifying active galactic nuclei (AGNs) in dwarf galaxies is an important step in studying black hole formation and evolution. In the research, we examine four dwarf galaxies that exhibit AGN-like signatures according to mid-IR color-color diagnostics used for larger galaxies. We perform photometric analysis on the nuclear star clusters and compare them to models of stellar popular evolution. Our results indicate that these galactic nuclei have ongoing star formation, are still at least partially obscured by clouds of gas and dust, and are most likely producing the extremely red AGN-like mid-IR colors.
Austin West
Fabrication of a Distributed Feedback Laser Based On Quasi-Two-Dimensional Perovskite
Distributed feedback (DFB) lasers use a diffraction grating built into the active region to create optical feedback, leading to lasing. We aim to create a novel superfluorescent DFB lasing device, where the light output is proportional to the square of the number of emitters. To date, we have successfully demonstrated using laser interference lithography (LIL) to create DFB grating structures in photoresist. By changing the angle of incidence of the laser beams in LIL, we have created gratings with several periodicities between 200 and 320 nanometers, which closely agree with the theoretical periodicities given by the Bragg condition. This will enable us to match the Bragg wavelength of the grating structure with an emission wavelength of our tunable, superfluorescent quasi-two-dimensional perovskite and construct novel devices.
Sean Cadigan
Using Optogenetics to Modify Sensory-Motor Networks in Echolocating Bats
Optogenetics is a new tool in neuroscience, used to target specific neurons for excitation, inhibition, or both, when exposed to a certain frequency of light. Utilizing these new tool, my lab targeted excitatory groups of neurons in the Superior Colliculus of two bat species, the Big Brown bat and the Mexican Free-Tailed bat. Our longterm objective was to classify the targeted neurons through the bat's behavioral response to excitation, understand the sequence of behaviors associated with sensory-motor integration, and begin building a profile for what stimulation protocol elicits the most significant behavioral effect.
3:00 PM in PAS 201 / Zoom Meeting
Refreshments in PAS 236, 2:30PM