Graduate Student Research

Research opportunities for graduate students abound. In addition to working directly with a Physics Department faculty member, graduate students also conduct research with faculty in Astronomy & Astrophysics, Chemistry, Geophysical Sciences, Biological Sciences, Molecular Engineering, as well as at Fermilab, Argonne, CERN, and many other facilities.

In many cases, graduate students can get involved in research immediately upon, and sometime before, beginning their first quarter in the program. The best way for graduate students to get involved in the research of his or her choice is to communicate with the faculty members working in their area(s) of interest to find out how to best proceed based on their specific situations. A great way to explore an experimental research group early-on is to satisfy the experimental physics requirement by doing a year-long project with that group.

Below, you will find a sampling of some of the fore-front-level research being done by our graduate students. You may also view the graduate research archive for previous profiles. Enjoy…

li-chung

Li-Chung Ha

Degrees:
- B.S., National Taiwan University, 2006 (Chemistry)
- M.S., National Taiwan University, 2009 (Physics)
Graduate Student (2010-pres), Dept. of Physics, James Franck Inst.
ResearchAtomic Physics
Awards: Grainger Graduate Fellowship (Dept. of Physics), Government Scholarships for Study Abroad (Taiwan)
Research Advisor: Cheng Chin 

Modern computers, based on silicon transistors, have experienced exponential year-on-year growth in computation power. Soon, this technology will reach the limitation defined by the tunneling effect of electrons in the semiconductor material. To respond to the increasing demand for faster data processing, a new type of computation technology is required. For data processing involving physical systems, the concept of quantum simulation was proposed by Richard Feynman. It involves the study of a complex system with a different system governed by the same equations, but which is relatively clean and controllable.

Ultracold atomic systems have been demonstrated as excellent candidates for doing quantum simulation. With the advantage of its cleanness and tunability, researchers are able to probe physical phenomena which are difficult to study in a complicated condensed matter system. Over the past decade, there have been numerous scientific results verifying the models shown in the textbook, e.g. realization of the Bose-Einstein condensate (BEC) and degenerate Fermi gas, demonstration of the Bose-Hubbard model, quantum magnetism, and quantum criticality.

The primary research direction of my thesis resides on engineering the band structure of a BEC in an optical lattice which is an optical potential created by interfering two laser beams. We load the condensate in a one dimensional optical lattice and phase modulate the lattice potential. The ground and the first excited bands from the lattice are coupled through the modulation, and the dispersion of the new admixed ground band evolves from having one single minimum to having two minima. This system exhibits effective ferromagnetism, and we directly observe the formation of domain and extract the correlation function.

Based on this new type of quantum phase, we are also able to simulate the roton which is a quasi-particle previously only observed in superfluid helium. The existence of roton in superfluid helium was speculated by Lev Landau to explain many experiments on the suppression of the superfluid critical velocity. In our system, the roton originates from the double-well dispersion in the shaken lattice, and can be controlled by both the atomic interaction and the amplitude of the modulation. We determine the excitation spectrum using Bragg spectroscopy and measure the critical velocity by dragging a weak speckle potential through the condensate. We observe good agreement between our measurement and the modified Bogoliubov model.

A future research direction is to study the scaling of the domain size versus the speed used to cross the phase transition in order to understand and simulate the early universe. As was predicted by Tom Kibble, the density of frozen-out cosmological defects, such as cosmic domains and strings, is set by the cooling rate of the universe after the Big Bang. Wojciech Zurek later extended the idea to condensed matter systems, which is the formation of vortices (an excitation with quantized angular momentum) in liquid helium after being quenched to the superfluid phase. The Kibble-Zurek mechanism is of particular interest in grand unified theories of symmetry-breaking phase transitions in the early universe, 10^{-35} s after the Big Bang. While it is infeasible to perform an experiment or classical computer simulation on a cosmological scale, a quantum simulator would be readily applicable to the question.

Publications

  • Roton-maxon excitation spectrum of Bose condensates in a shaken optical lattice, arXiv:1407.7157 (2014). L.-C. Ha, L. W. Clark, C. V. Parker, B. M. Anderson, C. Chin.
  • Anomalous thermoelectric transport in two-dimensional Bose gas, arXiv:1306.4018 (2013). E. L. Hazlett, L.-C. Ha, and C. Chin.
  • Direct observation of effective ferromagnetic domains of cold atoms in a shaken lattice, Nature Phys. 9, 769 (2013). C. V. Parker, L.-C. Ha, and C. Chin
  • Strongly interacting two-dimensional Bose gases, Phys. Rev. Lett. 110, 145302 (2013). L.-C. Ha, C.-L. Hung, X. Zhang, U. Eismann, S.-K. Tung, and C. Chin
  • Extracting density-density correlations from in situ images of atomic quantum gases, New Journal of Physics 13, 075019 (2011). C.-L. Hung, X. Zhang, L.-C. Ha, S.-K. Tung, N. Gemelke, and C. Chin.

Back to Top


eric

Eric Oberla

Degrees:
- B.S., Ohio State University, 2008 (Physics, Summa cum laude)
- M.S., University of Chicago, 2009 (Physics)
Graduate Student (2009-pres), Dept. of Physics, Enrico Fermi Inst.
Research: Experimental High-energy Physics / Instrumentation
Awards: Robert Millikan Fellowship (Dept. of Physics), Grainger Graduate Fellowship (Dept. of Physics), Nathan Sugarman Graduate Research Award (Enrico Fermi Institute), Best Talk Young Speaker (TIPP2014 Conference, Amsterdam)
Research Advisor: Henry Frisch

Many of the big open questions in particle physics, such as the matter-antimatter asymmetry in our present day universe or the nature of the neutrino mass, necessitate the building of larger, higher sensitivity, and more cost-effective particle detectors. In most of these detectors, some, if not all, of the detected signal is simply visible light (photons) that is created in various processes (Cherenkov, scintillation, etc) after a particle interaction. The pattern and timing of the photons collected by photo-sensors are analyzed to reconstruct and understand these rare interactions.

My graduate research has been broadly focused around the development of advanced photo-sensors as part of the Large Area Picosecond Photo-Detector (LAPPD) collaboration. Our diverse, interdisciplinary group is made up of particle physicists, electrical engineers, material scientists, and detector physicists. We are developing large-area micro-channel plate (MCP) detectors, which allow for the detection of individual photons with timing and spatial resolutions of ~50 picoseconds and a few millimeters, respectively. These properties, incorporated with new technologies that make these LAPPD MCP photo-sensors more cost effective than similar commercial products, open up new possibilities for detectors in particle physics and related fields.

My thesis project is the demonstration of a new type of particle detector relevant for neutrino physics, which takes advantage of the fine time and spatial resolutions of MCP photo-sensors. We call it the 'Optical Time Projection Chamber' (OTPC). The idea is somewhat similar to the liquid argon TPC, in which a neutrino-nucleon interaction creates ionization electrons that drift along field lines towards readout anode planes. The time-projection of these electrons onto the anode, which drift at a velocity of a few mm/microsecond, allow for amazing detail and 3D tracks of particles created in the neutrino interaction. What if a non-cryogenic, water-based detector could reconstruct particle tracks using 'drifted' optical photons, which travel at a few hundred thousand mm/microsecond? That's the idea of the OTPC: reconstructing 3D tracks of relativistic particles using the emitted Cherenkov photons. I've built a small-scale OTPC water detector that uses several MCPs with some minimal reflecting optics, and we will test its operation at an upcoming test-beam run at the Meson Test Beam Facility at nearby Fermilab National Accelerator Lab. A successful demonstration of the OTPC technology will be important first step scaling up to similar larger detectors capable of 'real physics', including: short baseline neutrino detectors, neutrinoless double beta decay, and even medical physics applications in positron emission tomography.

Lastly, I've spent a large part of my graduate career taking advantage of the industry-class design tools and electronics engineering expertise at the Electronics Design Group in the Enrico Fermi Institute. I led the design of an 'oscilloscope on-a-chip' Application Specific Integrated Circuit (ASIC), which is now the readout chip for the LAPPD photo-sensors and the OTPC detector. Named 'PSEC4', it was designed in 0.13 micron CMOS and its specific application is the digitization of waveforms sampled at up to 15 Gigasamples-per-second (~60 picosecond sampling steps). PSEC4 has been adopted by several other HEP groups around the country, and has been used as the readout ASIC for ground-penetrating radar in a civil engineering application, as well as for x-ray spectroscopy at Sandia National Lab.

Publications

  • E. Oberla, et al "A 15 GSa/s, 1.5 GHz bandwidth waveform digitizing ASIC", Nucl.Instrum.Meth. A735 (2014) 452-461. [arXiv:1309.4397].
  • B. Adams, et al, "Measurements of the gain, time resolution, and spatial resolution of a 20×20 cm2 MCP-based picosecond photo-detector," Nucl. Instrum. Meth. A732 (2013) 392-396.
  • B. Adams, et al, "A test-facility for large-area microchannel plate detector assemblies using a pulsed sub-picosecond laser", Rev. Sci. Instrum. 84, 061301 (2013).
  • M. Cooney, et al, "Multipurpose Test Structures and Process Characterization using 0.13 μm CMOS: The CHAMP ASIC", Physics Procedia 37 (2012) 1699-1706.

Back to Top


jennifer Jennifer Lin

Degrees:
- B.A., Princeton University, 2010 (Physics)
Graduate Student (2010-pres), Dept. of Physics, Enrico Fermi Inst.
Research: String Theory
Awards: National Science Foundation Graduate Fellowship (NSF), Sidney Bloomenthal Fellowship (Dept. of Physics)
Research AdvisorDavid Kutasov

Quantum field theory (QFT) is the framework which underlies our present-day understanding of elementary particles and their interactions. In its early history, QFT was formulated in a perturbative expansion around a non-interacting free theory. However many physical phenomena, such as color confinement of quarks (i.e. why no isolated quarks are observed) and mass generation for bound states (i.e. why nucleons are much heavier than their constituent quarks) lie outside this regime. Developing a better understanding of non-perturbative and strong coupling features of QFT's is thus of obvious interest.

One strategy is to study theories that share qualitative features with real world physics, yet are in some way simpler, allowing us to understand their strong coupling dynamics. Examples include the study of QFT's in lower dimensions, QFT's with extra symmetry (such as conformal symmetry and supersymmetry), or QFT's that exhibit strong-weak coupling duality, a general phenomenon where the same physics has both a strongly coupled description and an alternative, weakly coupled one.

My PhD work has revolved around deepening our understanding of field theory in this way. An example of a problem that I worked on recently is in supersymmetric QFT's in four spacetime dimensions. In 1994 N. Seiberg showed that N=1 SQCD, the supersymmetric generalization of the theory of quantum chromodynamics (QCD) that describes the strong force in nuclei, can be analyzed via a duality where it exhibits the same non-trivial physics at large distances as a different field theory. Extensions of his work have led to insights into the strong coupling dynamics of other supersymmetric QFT's, that exhibit qualitatively new features.

In one such extension, we can add extra matter fields to SQCD along with interactions for them. In 2003, K. Intriligator and B. Wecht classified all IR fixed points that can be obtained by deforming SQCD with adjoint matter. They found that the non-trivial fixed points corresponded to interaction terms that coincide with a mathematical structure called an ADE classification. The A and D theories in the classification were studied in the 1990's, where they were found to exhibit Seiberg-like duality, but there remained three models in the classification called E6, E7 and E8 which were not previously understood.

With my advisor David Kutasov, I analyzed the physics of the E7 theory by conjecturing a Seiberg dual description that passes many non-trivial checks. I also ruled out the existence of a qualitatively similar duality for the E6 and E8 cases. What happens for them remains an open problem. It is surprising that these two cases appear not to work like all the other ones, and suggests an opportunity for new insights into the structure of 4d QFT's.

Other topics that I have worked on while at Chicago include the dynamics of field theories in lower dimensions (2d theories with N= (0,2) supersymmetry and 3d non-SUSY Chern-Simons theory coupled to vector matter) as well as aspects of gauge/gravity duality, a strong-weak duality connecting field theories to higher-dimensional theories with gravity.

Publications:

  • D. Kutasov and J. Lin. N=1 Duality and the Superconformal Index. arXiv:1402.5411.
  • D. Kutasov and J. Lin. Exceptional N=1 Duality. arXiv:1401.4168.
  • D. Kutasov and J. Lin. (0,2) ADE Models From Four Dimensions. arXiv:1401.5558.
  • D. Kutasov and J. Lin. (0,2) Dynamics From Four Dimensions. Phys. Rev. D89, 085025 (2014). arXiv:1310.6032.
  • D. Kutasov, J. Lin, and A. Parnachev. Holographic Walking from Tachyon DBI. Nucl.Phys.B863:361-397 (2012). arXiv:1201.4123.
  • D. Kutasov, J. Lin, and A. Parnachev. Conformal Phase Transitions at Weak and Strong Coupling. Nucl. Phys. B858:155-195 (2012). arXiv:1107.2324.

Back to Top


jeremy Jeremy Neuman

Degrees:
- B.S., UCLA, 2010 (Physics with Honors)
- B.S., UCLA, 2010 (Mathematics)
- M.S., University of Chicago, 2011 (Physics)
Graduate Student (2010-pres) Dept. of Physics
Research: Theoretical Neuroscience, Nonequilibrium Statistical Mechanics
Awards: GAANN Fellowship (Dept. of Education), GSA Travel Award (Univ. of Chicago)
Research Advisors: Jack Cowan (Mathematics), Wim van Drongelen (Pediatric Neurology)

Generally in physics, model systems are close to equilibrium. In biology, however, this is almost never the case. Take for example the human brain, a structure as complicated as there is in the living world. It contains tens of billions of neurons, each with roughly one thousand connections. Yet many of its attributes lend it nicely to the study of non-equilibrium statistical mechanics and many body theory. Because of this, physicists can make large contributions to the field of theoretical neuroscience. My research seeks to use mean field and statistical field theories to explain a wide variety of neuronal dynamics, most of which we investigate with aggregate or "population" models. Primarily, we utilize the Wilson-Cowan equations, a set of nonlinear integro-differential equations designed to describe interactions at the mean-field level between the two general types of neurons, excitatory and inhibitory. These neurons connect in one of four ways: excitatory-excitatory, excitatory-inhibitory, inhibitory-excitatory, and inhibitory-inhibitory. From here, we can build an effective lattice or continuum model of the brain with only these assumptions.

One important question in neuroscience I've investigated is whether the resting state of the brain is critical and, if so, how it might organize itself into such a state. The idea behind this study is Self-Organized Criticality (SOC), a property of certain statistical systems which have their own mechanism for attraction to a critical point. The concept was developed to describe a wide array of phenomena across various fields of science, including physics, chemistry, economics, biology, and even sociology. In neuroscience, one manifestation of this self-tuning process is called synaptic plasticity, the ability of neurons to strengthen or weaken their connection strength over time. Previously, my advisors and I developed a model of plasticity, which, when coupled to a simple neural network with only an excitatory population, exhibits SOC. However, when we expanded our model to include inhibitory neurons, we found that the brain operates slightly below criticality, which we termed "self-organized near criticality." There is a large amount of data suggesting that this regime is optimal over being right at the critical point.

Recently, my advisors and I have been interested in the connection between localized and spreading neural activity. In the brain, experiments have shown that small inputs generate transient wave propagation while large inputs keep activity confined. One of our main efforts is to deterministically and stochastically simulate this effect because it could have implications, among other things, on our understanding of noise and consciousness, which at the neural network level is just the outgrowth of communication between brain regions. When activity cannot spread, the subject loses consciousness. On the other hand, spreading activity in an uncontrolled matter is the basis for a seizure, another topic of interest. Thus, it's clear that certain parameters in the brain must be met in order for us to be conscious but not constantly seizing. So far, we've found at the mean-field level that a slight redefinition in how clusters of neurons fire can answer this problem. As part of the remaining research for my Ph.D., I will further investigate the conditions on which neurons are able to communicate in a controlled fashion. This could lead to profound changes in the way we view a wide variety of neurological phenomena at the network level.

Selected Publications:

  • H. Meijer, T. Eissa, B. Kiewiet, C. Schevon, J. Neuman, A. Tryba, C. Marcuccilli, S. van Gils, W. van Drongelen, "Modeling Focal Epileptic Activity in the Wilson-Cowan model with Depolarization Block" Manuscript in preparation (2014).
  • J. D. Cowan, J. Neuman, and W. van Drongelen, "Self‐Organized Criticality and Near‐Criticality in Neural Networks" Criticality in Neural Systems, 465-484 (2014).
  • J. D. Cowan, J. Neuman, B. Kiewiet, & W. van Drongelen, "Self-organized criticality in a network of interacting neurons" Journal of Statistical Mechanics: Theory and Experiment, 2013(04), P04030 (2013).

Back to Top


cacey Cacey Stevens

Degrees:
- B.S., Southern University-Baton Rouge, 2008 (Physics with Honors)
- M.S., University of Chicago, 2010 (Physics)
Graduate Student (2008-pres) Dept. of Physics, James Franck Inst.
Research: Experimental Soft Condensed Matter
Awards: Robert Millikan Fellowship (Dept. of Physics), Chairman's Award for Distinguished Service (Dept. of Physics), NSF Graduate Research Fellowship, Chancellor's Award (Southern U), Willie H. Moore Scholarship (NSBP), Minority Scholarship (APS)
Research Advisor: Sidney Nagel

I am a Ph.D. candidate in experimental soft condensed matter physics working with Prof. Sidney Nagel. The Nagel group studies far-from-equilibrium phenomena on a macroscopic scale such as how liquids break apart or coalesce, how drops behave on a really hot surface, how sand flows and how things become jammed.

My research investigates the following question: How does a liquid drop behave when it impacts a dry solid surface? If it hits at a sufficiently high velocity, we expect the drop to splash, breaking apart into many smaller droplets. The splash, of course, depends on surface roughness and liquid properties such as surface tension or viscosity. For many years, researchers only considered these control parameters when studying drop impact. However, there is another surprisingly essential parameter for creating a splash: the ambient gas pressure. Our group has recently shown that one can prevent a drop from splashing by decreasing the ambient pressure below a threshold value that depends on liquid and surface properties. Using high-speed imaging, we have investigated how the surrounding air influences the splash dynamics.

For one of my projects, we developed a criterion for when a low-viscosity liquid drop will splash on smooth, dry glass. Even for this seemingly simple occurrence, it is difficult to define the onset of splashing in terms of all parameters. We determined the splash threshold pressure as a function of impact speed, liquid viscosity, and drop size. We found that by rescaling the axes in terms of dimensionless variables, we could collapse all our data onto a single master curve.

If the drop viscosity is increased to over three times that of water, the splash evolves more slowly than that of very low viscosity liquids.   In this regime we can see more clearly the splash evolution. As the drop spreads, a thin sheet of liquid is ejected and then breaks into droplets. We have shown that decreasing the air pressure acts to delay sheet ejection until, below a critical value, splashing stops entirely.

If the surface is rough, with an average roughness of a few microns, the impacting drop no longer ejects a thin sheet, as it does on a smooth surface, but promptly ejects droplets at contact. This allows a range of intermediate surface roughness for which no splash occurs. However, splashes on rough surfaces are still influenced by air pressure; as the pressure is lowered, droplet ejection is suppressed for prompt splashing. Thus, air pressure effects are robust for drop impact on dry surfaces. My research projects represent only a few directions that our group has taken to understand splashing phenomena.

While in graduate school, I have also been involved in several education and outreach activities. As a student coordinator of University of Chicago MRSEC Science club, an after-school program at a public elementary school near the University, I teach science concepts to young students through simple experiments and demonstrations. The students meet a diverse group of scientists and are encouraged to pursue careers in science. I have also gained experience engaging children in science as a guest lecturer for the Junior Science Cafes of the Museum of Science and Industry. Because of my interest in education, I am also involved in a research project that, using analysis methods from fluid mechanics, allows one to visualize patterns in educational data. In this work, I represent school performance scores on Illinois math and science exams as flow vectors and extract information about educational progress from the flow patterns. These flow charts could ultimately be used to show the most effective math and science educational programs in public schools.

Publications:

  • C. S. Stevens, A. Latka, and S. R. Nagel, "Comparison of Splashing in High and Low Viscosity Liquids" Phys. Rev. E 89, 063006 (2014).
  • C. S. Stevens, "Scaling of the Splash Threshold for Low Viscosity Fluids" EPL 106, 24001 (2014).
  • A. Latka, A. Strandburg-Peshkin, M. M. Driscoll, C. S. Stevens, and S. R. Nagel, "Creation of Prompt and Thin-Sheet Splashing by Varying Surface Roughness or Increasing Air Pressure" Phys. Rev. Lett. 109, 054501 (2012).
  • M. M. Driscoll, C. S. Stevens, and S. R. Nagel, "Thin Film Formation During Splashing of Viscous Liquids" Phys. Rev. E 82, 036302 (2010).

Back to Top


kyle Kyle Story

Degrees:
- B.A., Cornell University, 2007 (Physics)
- B.A., Cornell University, 2007 (Mathematics)
- M.S., University of Chicago, 2009 (Physics)
Graduate Student (2008-pres) Dept. of Physics, Kavli Institute
Research: Experimental Cosmology
Awards: Grainger Graduate Fellowship, Robert R. McCormick Fellowship (Dept. of Physics), William Rainey Harper Dissertation Fellowship (Physical Sciences Division), NSF Graduate Fellowship Honorable Mention
Research Advisor: John Carlstrom

As physicists, we live in a remarkable time in which we can quantitatively study our entire observable universe. Over the past few decades, physicists have made striking progress towards a robust standard model of cosmology; we know we live in a universe that continues to expand from a hot, dense origin, and we have a conceptual framework that successfully describes phenomena from the scale of single atoms (such as the formation of the light elements) up to the largest scales in the observable universe. Yet much remains mysterious. This standard model posits that only ~5% of the total energy density of the universe is comprised of ordinary matter, while poorly understood dark matter and dark energy contribute the remaining ~25% and ~70%, respectively. According to this model, the very early universe underwent a period of super-luminal expansion known as "inflation." We know that neutrinos have mass but have not measured the absolute mass, and there are tantalizing hints that neutrino physics could be more complicated than the standard 3-flavor picture.

Advances in the field of cosmology are driven by measurements and observations. One of the richest sources of information is the Cosmic Microwave Background (CMB). Serendipitously discovered in 1964, the CMB is thermal radiation left over from the hot, dense early universe. The universe cooled as it expanded from its hot, dense origin, and after ~380,000 years the ambient temperature dropped below the ionization energy of hydrogen. At this transition, the universe rapidly became neutral as most of the free electrons and protons paired off to form hydrogen, and the universe quickly became transparent to light. The photons that last scattered at this time have been streaming through the universe ever since, and comprise the CMB. Thus, observations of the CMB can give physicists an incredibly informative snap-shot picture of the infant universe.

In my research, I observe and study the CMB to understand the basic physics of how the universe works. Our group built and continues to operate the South Pole Telescope (SPT), a millimeter-wave telescope located at - can you guess it? - the south pole in Antarctica. In the austral summer of 2011-2012, I helped deploy a new polarization-sensitive camera for the SPT, called SPTpol. As a part of this research I have traveled to the south pole four times, with my fifth trip scheduled for this January.

In my graduate career, I have used data collected with the SPT to study several different science topics. As CMB photons travel through the universe, some will traverse through clusters of galaxies and will scatter off of intra-cluster gas, thus distorting the primary CMB spectrum in a process known as the Sunyaev-Zel'dovich effect (SZE). We use these distortions in SPT data to find and study these clusters of galaxies. Clusters of galaxies are informative since they trace large-scale dark matter structures and are sensitive to the composition and expansion history of the universe. In 2011 the Planck satellite published its first catalog of SZE-selected clusters; I led observations and an analysis which used the SPT to confirm the five previously unconfirmed clusters in the southern hemisphere from that catalog.

In 2012, I led an analysis in which we used data from the full 2500 square-degree SPT-SZ survey to measure the power spectrum of the CMB. The power spectrum is a powerful way to quantify the statistical properties of the anisotropy in the CMB. This anisotropy arises from - and therefore probes - a wealth of interesting physics including the energy composition and expansion history of the universe, particle interactions at early times, and potential gravitational waves from inflation. Additionally, effects closer to today imprint signals in the CMB, including the SZE and gravitational lensing by large-scale dark matter structures. In a pair of papers resulting from the analysis I led, we published the most precise measurement of the CMB power spectrum over angular scales between ~0.06 and 0.25 degrees, and discussed the resulting constraints on models of cosmology.

For my thesis work, I am now focusing on the signal of gravitational lensing in the measurements taken with SPTpol. Gravitational lensing bends the paths of CMB photons as they travel from the surface of last scattering to Earth, thus distorting the anisotropy pattern of the CMB. The strength of this gravitational lensing signal is sensitive to the structure of ordinary and dark matter, cosmic acceleration (dark energy), neutrino physics, and the nature of gravity itself. Finally, gravitational lensing distorts the polarization patterns in the CMB, creating odd-parity swirl-patterns. Similar swirl-patterns could have been created by gravity waves from inflation in the very early universe; thus understanding and removing the lensing signal will be important in the search for these signals of inflation. The information we will gain by studying gravitational lensing in the CMB with SPTpol will shed light on all of these topics.

Selected Publications:

  • Hou, et.al, "Constraints on Cosmology from the Cosmic Microwave Background Power Spectrum of the 2500-square degree SPT-SZ Survey" arXiv:1212.6267 (2012).
  • Story, et.al., "A Measurement of the Cosmic Microwave Background Damping Tail from the 2500-square degree SPT-SZ Survey" arXiv:1210.7231 (2012).
  • Story, et.al., "South Pole Telescope software systems: control, monitoring, and data acquisition" Proceedings of SPIE 8451 (2012); arXiv:1210.4966 (2012).
  • Story, et.al., "South Pole Telescope Detections of the Previously Unconfirmed Planck Early Sunyaev-Zel'dovich Clusters in the Southern Hemisphere" Astrophys Journal Lett 735 L36 (2011).

Back to Top