The Physics Department and the Brown Theoretical Physics Center are pleased to present a BTPC IDEA Seminar featuring Wenzer Qin of MIT on Thursday, 10/5 at 12 p.m. in room 212 of the Barus Building.

Lunch will be provided.

Title: Probing Exotic Energy Injection with the CMB and Early Star Projection

Abstract: Dark matter interactions with Standard Model particles can inject energy at early times, altering the standard evolution of the early universe. In particular, this energy injection can perturb the spectrum of the cosmic microwave background (CMB) away from that of a perfect blackbody, alter the CMB anisotropy spectrum, and affect processes by which the first stars form. For this study, I will discuss recent work to upgrade the DarkHistory code package to more carefully track interactions among low energy electrons, hydrogen atoms, and radiation, in order to accurately compute the evolution of the CMB spectral distortion in the presence of Dark Matter energy injection. I will show results for the contribution to the spectral distortions from redshifts z < 3000 for arbitrary energy injection scenarios, new CMB anisotropy constraints on light dark matter, as well as the effect of exotic energy injection on early star formation.

The Physics Department is pleased to present the Pat and Tony Houghton Condensed Matter Seminar Series featuring Professor Arnold Mathijssen, University of Pennsylvania on Thursday, October 5 at 4:00 p.m. in BH190.

TITLE:
Collective Functionalities Emerging in Microbial Active Matter

Abstract:

Microbes often cooperate to withstand predators and compete even with multicellular organisms. Together, they can achieve functåionalities that alone they cannot. However, this puzzle of how biological self-organization emerges from the collective dynamics of individual constituents remains unsolved. In this talk, I will discuss some of these collective functionalities, including communication, navigation, and cooperative nutrient transport. First, we focus on ultra-fast communication through “hydrodynamic trigger waves”, signals between cells that propagate hundreds of times faster than their swimming speed [1]. Second, we will explore how bacteria can reorient against flows and contaminate reservoirs upstream [2]. Third, we consider how bacteria generate their own flows to transport nutrients [3], and how “active carpets” like biofilms can lead to enhanced non-equilibrium diffusion [4]. Together, these ideas help us understand emergent self-organization in biological systems and the design space of active materials. [1] Mathijssen et al. “Collective intercellular communication through ultra-fast hydrodynamic trigger waves,” Nature 571, 560-564 (2019) [2] Mathijssen et al. “Oscillatory surface rheotaxis of swimming E. coli bacteria,” Nat. Commun. 10, 3434 (2019) [3] Jin et al. “Collective entrainment and confinement amplifies transport by schooling micro-swimmers”, Phys. Rev. Lett. 127: 088006 (2021) [4] Guzman-Lastra et al. “Active carpets drive non-equilibrium diffusion and enhanced molecular fluxes,” Nat. Commun. 12: 1906 (2021) BIO: Arnold Mathijssen was named ’30 under 30’ by Scientific American and was awarded the Sir Sam Edwards PhD Thesis Prize for his work in group of Julia Yeomans FRS at the University Oxford (2016). Supported by an HFSP cross-disciplinary fellowship, he moved to the lab of Manu Prakash at Stanford University, where the American Physical Society presented him the Charles Kittel Award (2019). He is now Assistant Professor of Physics & Astronomy at UPenn, and co-chair of the 2024 CUWiP Conference for Undergraduate Women in Physics.

SUBRA SURESH
Professor at Large, Brown University
President, Global Learning Council, Villars-sur-Ollon, Switzerland
Vannevar Bush Professor of Engineering Emeritus, Massachusetts Institute of Technology
and Former Director, National Science Foundation
will present a special lecture: “Innovation 4.0 for Humanity 4.0”

Abstract: Innovation is catalyzed at an ever-accelerating pace by advances across a wide spectrum of intellectual disciplines and nurtured across sectors by academia, industry, philanthropy, and government. It provides the foundation for translating ideas, scientific discoveries, and human creativity into products, processes, and services that benefit individual citizens as well as local and global society. In this lecture, some key features of successful ecosystems for responsible innovation will be examined, with examples and case studies, from the perspectives of historical evolution, best practices, policy development, and societal impact. We also examine the unprecedented opportunities and challenges at the intersections of technology and humanity in the era of the Fourth Industrial Revolution.

Our discussion will consider how these intersections are further propelled by advances in artificial intelligence and machine learning and by the unique convergence of the physical, digital and biological worlds.

A wine and cheese reception will follow. 

The Physics Department is pleased to present the Pat and Tony Houghton Condensed Matter Seminar Series featuring Professor Jordan Hachtel, Oakridge National Laboratory on Thursday, October 12 at 4:00 p.m. in BH190.

Title and abstract TBD.

The Physics Department is pleased to present the Pat and Tony Houghton Condensed Matter Seminar Series featuring Professor Chinedu Ekuma, Lehigh University on Thursday, October 19 at 4:00 p.m. in BH190.

Title and abstract TBD.

The Physics Department is pleased to present a colloquium featuring Professor Tom Solomon, Bucknell University on Monday, October 23 at 4:00 p.m. in BH168. Refreshments will be served at 3:45 p.m.

Title & Abstract TBD.

Please join leaders from the National Academies of Sciences, Engineering and Medicine and the Brown STEMM community for a daylong conference discussing strategies to advance antiracism and DEI in science and medicine. Faculty, students, trainees, administrators, and alumni with an interest in DEI efforts in STEMM are encouraged to attend this free event.

The agenda includes:

• Presentation of the NASEM report by Joan Y. Reede, MD, MS, MPH, MBA, Dean for Diversity and Community Partnership, Harvard Medical School, and Emily A. Vargas, PhD, Program Officer, Board on Behavioral, Cognitive, and Sensory Sciences, Division of Behavioral and Social Sciences, and Education, The National Academies of Sciences, Engineering and Medicine;
• Panel discussions with Tejal A. Desai ’94, PhD, Sorensen Family Dean of Engineering, Dean of Engineering, Professor of Engineering; Leah K. VanWey, PhD, Dean of the Faculty, Office of the Provost; Andrew G. Campbell, PhD, Professor of Medical Science, AAAS Fellow, ASCB Fellow, among other distinguished panelists;
• Closing reception.

The Physics Department is pleased to present the Pat and Tony Houghton Condensed Matter Seminar Series featuring Professor Eslam Khalaf, Harvard University on Thursday, October 26 at 4:00 p.m. in BH190.

Title and abstract TBD.

The Physics Department is pleased to present the Pat and Tony Houghton Condensed Matter Seminar Series featuring Nikita Kavokine of the Flatiron Institute and The Max Planck Institute for Polymer Research on Thursday, October 26 at 4:00 p.m. in BH190.

Title and abstract TBD.