Skip to Content

Colloquium

« Previous Page  Page 3 of 13  Next Page »
February 28, 2017

The First Four Months of Gravitational Wave Astronomy

Colloquium Preview

Date: Thursday, March 2nd, 2017

Speaker:  Ben Farr, University of Chicago

Abstract:

On September 14, 2015 LIGO made the first direct detection of gravitational waves, marking the true beginning of gravitational wave astronomy. I will present the methods behind the detection and characterization of LIGO’s binary black hole mergers, and what they have taught us about compact binaries thus far. I will focus in particular on the important astrophysical ramifications of these initial detections, and what we can be expected to learn in the near future from gravitational-wave astronomy.

Host: Jim Brau

Time: 4:00-5:00pm
Location:  100 Willamette Hall

Colloquium Archive

February 24, 2017

Silicon, Straws, and SUSY:Searches for Supersymmetry featuring the ATLAS Inner Detector

Colloquium Preview

Date: MONDAY, February 27th, 2017

Speaker:  Laura Jeanty, Lawrence BerkeleyNational Laboratory, Berkeley, CA

Abstract:

The keystone of the standard model of particle physics, the Higgs Boson, was discovered during the first run of the Large Hadron Collider (LHC). The LHC is halfway through its second run, with higher energy and higher intensity collisions providing a dataset ripe for discovery of physics beyond the standard model. Supersymmetry remains a promising theory for new physics accessible at the LHC. The inner tracking detector plays a crucial role in many searches for supersymmetry on the ATLAS experiment. In this talk, I will discuss the current status and outlook of supersymmetry searches by ATLAS, with a focus on the different ways in which the inner detector extends our sensitivity to new particles.

Host: Ray Frey

Time: 4:00-5:00pm
Location: 123 PACIFIC HALL

Colloquium Archive

February 21, 2017

From Gravitons to Electrons: the Discovery of GW151226

Colloquium Preview

Date: Thursday, February 23rd, 2017

Speaker:  Sarah Caudill, University of Wisconsin-Milwaukee

Abstract:

LIGO’s detection of the first gravitational wave signal, GW150914, ushered in the era of gravitational wave astronomy with quite a bang, giving us a measurement of the heaviest stellar mass black holes to date and providing new stringent tests of general relativity. However, the detection of the second signal, GW151226, on December 26, 2015 was arguably just as exciting. I will describe the technology that allowed this signal to be detected just 70 seconds after arrival. Additionally, GW151226 spent nearly 55 cycles in LIGO’s sensitive band compared to only 10 cycles for GW150914. I will discuss the precise measurements of the compact binary parameters that were afforded by this longer signal. Finally, I will describe how these two gravitational wave detections inform our predictions for more discoveries in the near future.

Host: Jim Brau

Time: 4:00-5:00pm
Location: 100 Willamette Hall

Colloquium Archive

February 17, 2017

Measuring Storms in Space-Time: Astronomy with Gravitational Radiation

Colloquium Preview

Date: MONDAY, February 20th, 2017

Speaker:  Robert Ward, Department of Quantum Science, Australian National University

Abstract:

On September 14, 2015, the LIGO detectors recorded the first direct observation by humankind of gravitational waves — space-time distortions generated by objects with extreme gravity. These waves propagate over astrophysical distances and can be detected by the modulation imposed on the optical path of a suspended mirror laser interferometer. We now have a new form of radiation with which to study the Universe. The level of displacement sensitivity which enabled the first detections, less than 1 part in 10,000 of a proton diameter, mandates not only significant isolation from environmental noise, but also a readout scheme capable of measurement at this level. I will discuss gravitational waves and the technology developed to detect them, including the optical metrology techniques that enable the Advanced LIGO detectors to reach their extraordinary sensitivity and how we extract the signals necessary to control the interferometer. I will describe what we have observed so far and what we hope to learn about the universe with this new astronomical messenger

Host: Jim Brau

Time: 4:00-5:00pm
Location: 123 PACIFIC HALL

Colloquium Archive

February 14, 2017

Science on the Edge: Critical Phenomena in Granular Systems

Colloquium Preview

Date: Thursday, February 16th, 2017

Speaker:  Susan Lehman, Claire Booth Luce Associate Professor of Physics at The College of Wooster in Wooster, Ohio

Abstract:   A granular system behaves in some ways like a liquid with an ability to flow, and in some ways like a solid with a stable fixed structure if undisturbed. A tiny stimulus to the pile most often results in only a small response, but the same small stimulus can also create an unpredictable and catastrophic collapse of the pile. These collapses occur both in natural settings, with hazards such as landslides and snow avalanches, and in industrial situations, where granular materials like sand or agricultural grains need to flow freely. We use a simple experimental system – a 3D conical pile of uniform beads – in order to model these real-world physical systems. We investigate the dynamic response of the pile by recording avalanches from the pile over the course of tens of thousands of bead drops. The resulting behavior is well-characterized by universal power laws and scaling functions, relating this work to the broader study of critical systems.
All of these results were obtained at The College of Wooster, a liberal arts college with a particular focus on mentored undergraduate research. As part of the talk, I will discuss how work at a liberal arts college differs from work at a large research university, and suggest ways to prepare for alternative academic careers.

Host: Ray Frey

Time: 4:00-5:00pm
Location: 100 Willamette Hall

Colloquium Archive

February 10, 2017

A New Era of Gravitational Wave Astronomy

Colloquium Preview

Date: MONDAY, February 13th, 2017

Speaker:  Evan Goetz, Max Planck Institute for Gravitational Physics, Germany

Abstract:

With the first observations of gravitational waves by the Advanced LIGO detectors in September 2015, a new era of gravitational wave astronomy has begun. In this talk, I will discuss the first gravitational wave observations, describe the Advanced LIGO detectors and how they are calibrated, and summarize the analysis that uncovered the binary black hole coalescence. In addition, I will discuss other searches for continuous gravitational waves, a promising probe to study neutron star physics.

Host: Jim Brau

Time: 4:00-5:00pm
Location: 123 PACIFIC HALL

Colloquium Archive

February 3, 2017

A Stroll Through Quantum Walks

Colloquium Preview

Date: February 9th, 2017

Speaker: Barry Sanders, Institute for Quantum Science and Technology, Department of Physics and Astronomy, University of Calgary, Calgary, Canada

Abstract:

The subject of quantum walks emerged from considerations of the ubiquitous random walks inherent in diffusion in physics and chemistry, randomized algorithms in computer science, and Wiener measures in mathematics. From its humble beginnings as a generalization of random walks, quantum walks have emerged into a large-scale theoretical and experimental research area that extends into a wide spectrum of areas including universal quantum computing, simulating topological phenomena, and modeling energy transport in certain biological molecular complexes. I begin with a primer on quantum walks and then cover current hot theoretical studies and experimental implementations of quantum walks.

Host: Michael Raymer

Time: 4:00-5:00pm
Location: 100 Willamette Hall

Colloquium Archive

January 27, 2017

Opening the Gravitational Wave Universe: Extending the Reach of Gravitational Wave Detectors

Colloquium Preview

Date: February 2nd, 2017

Speaker: Sheila Dwyer, LIGO Hanford Observatory

Abstract:

With the first direct detection of gravitational waves, the LIGO detectors have opened a new field of astrophysics, discovered a new class of massive stellar mass black holes, and enabled tests of general relativity.  To make these discoveries, we built the most sensitive displacement meters yet, measuring displacements of one thousandth of a proton diameter over a 4 kilometer baseline.  This talk will focus on the fundamental noise sources which limit the performance of gravitational wave detectors, and the possibilities for extending their reach.  Squeezed states of light, cryogenic operation and new optical materials have the potential to dramatically increase the distances at which gravitational wave observations can be made.  In a new and larger facility, LIGO style detectors could observe compact object binaries from the earliest periods of star formation, making complete surveys of an epoch difficult to observe with optical telescopes.

Host: Jim Brau

Time: 4:00-5:00pm
Location: 100 Willamette Hall

 

Colloquium Archive

January 23, 2017

Color and Shape: The Quantum State of a Single Photon and its Manipulation

Colloquium Preview

Date: January 26th, 2017

Speaker: Brian J. Smith, University of Oregon

Abstract:

Just over a century ago Max Planck introduced the quantized energy exchange between electromagnetic field modes in an optical cavity and the atoms comprising the walls at finite temperature to derive the spectral energy density of black body emission. Shortly thereafter, Einstein proposed that not only was the energy exchanged between the field and matter quantized, but that the radiation itself was quantized. He proposed that each light quantum, now called a photon, carries energy that is proportional to the frequency of the optical field mode. The frequency of a single photon is a central property that defines its physical state. Indeed, the full quantum state of a single photon is directly related to the electromagnetic field mode function that it occupies. Thus, we see that the central frequency of a single photon, often thought of as a defining property of a single light quantum, is not immutable, but can be modified just as the classical frequency of light can be manipulated. Here, we report the first experimental demonstration of deterministic spectral manipulation of single photons achieved by application of controlled spectral and temporal phases. These techniques lay the ground for future quantum wavelength- and time-division multiplexing applications and facilitate interfacing of different physical platforms where quantum information can be stored and manipulated.

Time: 4:00-5:00pm
Location: 100 Willamette Hall

 

Colloquium Archive

January 19, 2017

January 19th Physics colloquium has been cancelled.

The January 19th Physics colloquium has been cancelled due to weather related travel cancellations.

 

 

« Previous Page  Page 3 of 13  Next Page »