Alumni

The Age of Living Machines: How Biology Will Build the Next Technology Revolution

With an anticipated world population of over 9.5 billion by 2050, we face an unprecedented challenge to sustainably provide sufficient food, water, energy and healthcare. Convergence, the merging of previously distinct disciplines, has emerged as a powerful model with untold potential to drive a new cycle of innovation-based economic growth. Bringing together insights and discoveries from the life, engineering, computation and physical sciences holds the promise of accelerating discovery and the development of new technologies to meet the 21st century’s needs.

What is a 'Cause,' and Why Does it Happen Before the Effect?

The physics of the time orientation of causation is more subtle than what it looks like superficially. For a long while it was reduced to a mere linguistic issue (a “cause” is just the term of a correlation that happens earlier, Hume). As emphasized by Russell, there is no time orientation in fundamental physics. But causation was later better understood as an essential notion in the context of an agent having choices, which after all is our own common context. This traces the time orientation of causation to the time orientation of agency.

NPA Zoom Seminar, Kimmy Wu, SLAC/KIPAC, "Improved Constraint on Primordial Gravitational Waves with Delensing"

Inflation generically predicts a background of primordial gravitational waves, which generate a primordial B-mode component in the polarization of the cosmic microwave background (CMB). The measurement of such a B-mode signature would lend significant support to the paradigm of inflation. Observed B modes also contain a component from the gravitational lensing of primordial E modes, which can obscure the measurement of the primordial B modes.

NPA Zoom Seminar, Govert Nijs, MIT, "A Transverse Momentum Differential Global Analysis of Heavy Ion Collisions"

The understanding of heavy ion collisions and its quark-gluon plasma formation requires a complicated interplay of rich physics in a wealth of experimental data. In this work we compare for identified particles as a function of transverse momentum both the spectra and the anisotropic flow coefficients for both PbPb and pPb collisions. We do this in a model including a free streaming prehydrodynamic phase with variable velocity v_fs, thereby widening the scope of initial conditions. During the hydrodynamic phase we vary three new second order transport coefficients.

NPA Zoom Seminar, Zhilei Xu, MIT, "Precision Cosmology: from the CMB to 21-cm Observations"

Over the past decades, the discovery and characterization of the cosmic microwave background (CMB) have marked the beginning of precision cosmology. At lower redshifts, future 21-cm signals from neutral hydrogen atoms also have great potential for cosmological and astrophysical studies. Observing 21-cm signals at different frequency bands produces a tomographic view of the universe. These observations will transform our current understanding of cosmology, commencing the 21-cm precision cosmology.

NPA Zoom Seminar, Devin Walker, Dartmouth College, "Two Stories at the Intersection of Particle Physics and Gravitational Waves"

First Story:

NPA Zoom Seminar, Jean-Francois Paquet, Duke, "Constraining the Viscosities of QCD with Relativistic Heavy Ion Collisions"

Fluids can be characterized by macroscopic properties such as viscosities or an equation of state. While the macroscopic properties of everyday fluids are determined by the electromagnetic interaction, an ensemble of fluids encountered in astrophysics and nuclear physics is dominated by the strong nuclear interaction. Relativistic collisions of heavy nuclei, performed at the Large Hadron Collider and the Relativistic Heavy Ion Collider, concentrate sufficient energy at the point of impact to produce a strongly-coupled plasma of deconfined nuclear matter.

NPA Zoom Seminar, Ruby Byrne, University of Washington, "Measuring the Epoch of Reionization: Progress, Challenges, and Next Steps for High Redshift 21 cm Cosmology"

The 21 cm emission line from neutral hydrogen represents a promising observational probe of cosmological evolution. In particular, measuring the highly redshifted 21 cm emission from the Epoch of Reionization (EoR) will illuminate a crucial and currently poorly understood period in cosmological history. The EoR denotes the period when radiation from early galaxies and black holes ionized the intergalactic medium.

NPA Zoom Seminar, Ho San Ko, LBL, "Accessing Generalized Parton Distributions at Jefferson Lab"

An exciting scientific frontier is the 3-dimensional exploration of nucleon (and nuclear) structure: nuclear femtography. The study of Generalized Parton Distributions (GPDs) captures the images of the transverse position distributions of fast moving quarks. Therefore, they provide richer information about the nucleon structure than the well known form factors and parton distribution functions. GPDs are accessible via exclusive reactions, where all particles in the final state are identified.

NPA Zoom Seminar, Stefania Amodeo, Cornell University, "Halo gas thermodynamics from the CMB: results from the Atacama Cosmology Telescope DR5"

The thermodynamic properties of the ionized baryons in galaxies, groups, and clusters encode the effects of the assembly history and feedback processes that shape galaxy and cluster formation. These properties can be studied through the imprints that the scattering of cosmic microwave background (CMB) photons off the free-electron gas in galaxies and clusters leave on high resolution CMB maps: the thermal and kinematic Sunyaev-Zel’dovich effects.