KICP Seminars & Colloquia
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KICP Seminars & Colloquia, Current and Future
Today's Seminar
Upcoming Seminars
Seminar schedule for Current (Spring 2012) & Future Quarters
March 28, 2012
Wednesday colloquium | William Kinney
Univ. at Buffalo, SUNY | Inflation, or What? [Abstract] |
March 30, 2012
Friday noon seminar | Matthew Colless
Australian Astronomical Observatory | Expansion, acceleration and growth rate of the universe from the 6dF and WiggleZ surveys [Abstract] |
April 4, 2012
Astronomy Colloquium | Sarah Shandera
Pennsylvania State University | New Observational Handles on the Primordial Universe [Abstract] |
April 5, 2012
Friday noon seminar | Albert Stebbins
Fermilab | WYSIWYG Space-Time [Abstract] |
April 11, 2012
Wednesday colloquium | Laura Cadonati
University of Massachusetts Amherst | Probing the Transient Universe with Gravitational Waves [Abstract] |
April 13, 2012
Friday noon seminar | Rosalind E Skelton
Yale University | The rise of the red sequence: Exploring hierarchical growth with models and future prospects with the 3DHST and CANDELS surveys [Abstract] |
April 18, 2012
Astronomy Colloquium | Risa Wechsler
KIPAC/Stanford University | The Galaxy-Halo Connection Across Mass and Time [Abstract] |
April 20, 2012
Friday noon seminar | Will Percival
University of Portsmouth | First results from galaxy clustering in the BOSS survey [Abstract] |
April 25, 2012
Wednesday colloquium | Rachel Somerville
Rutgers University | The Other Side of Galaxy Formation: modeling gas in and around galaxies [Abstract] |
April 27, 2012
Friday noon seminar | Oliver Zahn
University of California, Berkeley | New Cosmology from the South Pole Telescope [Abstract] |
May 2, 2012
Astronomy Colloquium | Claudia de Rham
Case Western Reserve University | Massive Gravity and Cosmology [Abstract] |
May 4, 2012
Friday noon seminar | Reina Maruyama
University of Wisconsin-Madison | DM-Ice: a Search for Dark Matter at the South Pole [Abstract] |
May 9, 2012
Wednesday colloquium | John Beacom
Ohio State University | Diffuse Supernova Neutrino Background [Abstract] |
May 11, 2012
Friday noon seminar | Laura Newburgh
Princeton University | ACTPol: A Polarized Receiver for the Atacama Cosmology Telescope [Abstract] |
May 16, 2012
Astronomy Colloquium | Gil Holder
McGill University | Gravitational Lensing of the Cosmic Microwave Background [Abstract] |
May 18, 2012
Friday noon seminar | Vikram V Dwarkadas
University of Chicago | The Acceleration and Escape of Particles in Young Supernova Remnants [Abstract] |
May 23, 2012
Wednesday colloquium | Jonathan Feng
UC Irvine | Status of SUSY and SUSY Dark Matter [Abstract] |
May 25, 2012
Friday noon seminar | Tristan L Smith
UC Berkeley | Looking for cracks in the standard cosmological model: neutrinos and non-Gaussianity [Abstract] |
May 30, 2012
Astronomy Colloquium | Mike Gladders
The University of Chicago | TBA |
June 8, 2012
Friday noon seminar | Ivone Albuquerque
University of Sao Paulo | TBA [Abstract] |
Wednesday colloquia
- March 28, 2012 | 3:30 PM | BSLC 109
Inflation, or What?
William Kinney, Univ. at Buffalo, SUNY
Note: Refreshments begin at 3:00 pm in LASR conference room.
Inflation has emerged as the leading model for the very early universe, not least because of the theory's remarkably successful prediction for the form of the CMB anisotropy. I ask the question: is inflation the only way to match the data? If not, what do the possible alternatives look like?
- April 11, 2012 | 3:30 PM | BSLC 109
Probing the Transient Universe with Gravitational Waves
Laura Cadonati, University of Massachusetts Amherst
Note: Refreshments begin at 3:00 pm in LASR conference room.
The Laser Interferometer Gravitational-wave Observatory (LIGO) and its sister project Virgo aim to achieve, within this decade, the first direct detection of gravitational waves and tune in to the gravitational-wave soundtrack of the Universe. The information from gravitational waves, complementary to the multi-wavelength electromagnetic spectrum, neutrinos and cosmic rays, will contribute to a more complete, understanding of some of the most violent and energetic events in the universe, such as gamma-ray bursts, soft-gamma repeaters, supernovae, and glitching pulsars.
In this talk I will give an overview of ongoing efforts towards the realization of this new gravitational wave astrophysics, and of how electromagnetic and neutrino observations and the theoretical understanding of source dynamics are coupled into gravitational wave analysis. I will present selected results from the initial generation of LIGO and Virgo data and outline prospects for discovery in the advanced detector era, with particular focus on transient signatures.
- April 25, 2012 | 3:30 PM | BSLC 109
The Other Side of Galaxy Formation: modeling gas in and around galaxies
Rachel Somerville, Rutgers University
Note: Refreshments begin at 3:00 pm in LASR conference room.
The Other Side of Galaxy Formation: modeling gas in and around galaxies
Much observational work has focused on measuring the star formation rate in galaxies and its cosmic evolution. However, the supply rate of fuel for star formation (cold dense gas), the internal processes that regulate its conversion into stars, and the feedback processes that regulate star formation, all remain poorly understood both theoretically and observationally. I will discuss recent attempts to build more sophisticated theoretical models to predict the multi-phase gas content of galaxies, which in particular will allow us to make connections between galaxies as observed via stellar emission, emission in CO or HI, and in absorption.
- May 9, 2012 | 3:30 PM | BSLC 109
Diffuse Supernova Neutrino Background
John Beacom, Ohio State University
Note: Refreshments begin at 3:15 pm
The Super-Kamiokande detector, shown here, is roughly 40 m in all directions. At any instant, it contains 10-100 neutrinos that were born in core-collapse supernovae across the cosmos. Can you spot them? Look for the red-and-white-striped sweaters.
The diffuse supernova neutrino background (DSNB) is the weak glow of MeV neutrinos and antineutrinos from distant core-collapse supernovae. The DSNB has not been detected yet, but the Super-Kamiokande upper limit on the electron antineutrino flux is close to predictions, now quite precise, based on astrophysical data. If SK is modified with dissolved gadolinium to reduce detector backgrounds, then it should detect the DSNB at a rate of a few events per year, providing a new probe of supernova neutrino emission and the cosmic core-collapse rate. Neutrino astronomy, while uniquely powerful, has proven extremely difficult - only the Sun and the nearby Supernova 1987A have been detected to date - so the promise of detecting new sources soon is exciting indeed.
- May 23, 2012 | 3:30 PM | BSLC 109
Status of SUSY and SUSY Dark Matter
Jonathan Feng, UC Irvine
Note: Refreshments begin at 3:00 pm in LASR conference room.
Weak-scale supersymmetry has long been a dominant paradigm for physics beyond the standard model and particle dark matter, but it is now being challenged by a wealth of experimental data. I will begin by reviewing attempts to quantify naturalness in supersymmetry, stressing the many subjective
choices that impact the results both quantitatively and qualitatively. I then summarize experimental
results that most directly challenge weak-scale supersymmetry, including recent results from the LHC. Some
models are excluded or under great tension, while others remain perfectly viable. For the latter, I will outline the key features, current status, and implications for colliders and dark matter searches.
Friday noon seminars
- March 30, 2012 | 12:00 PM | LASR Conference Room
Expansion, acceleration and growth rate of the universe from the 6dF and WiggleZ surveys
Matthew Colless, Australian Astronomical Observatory
Expansion, acceleration and growth rate of the universe from the 6dF and WiggleZ surveys
The 6dF Galaxy Survey has mapped 125,000 galaxies at a median redshift z=0.05 over the whole southern hemisphere, while the WiggleZ survey has mapped 220,000 star-forming galaxies at redshifts out to z=1 over a cubic gigaparsec. In combination, these surveys measure the evolution of the power spectrum of the galaxy distribution, including the features due to the baryon acoustic oscillations and redshift-space distortions. These measurements yield the expansion history of the universe over the last 8 billion years, and provide new and model-independent determinations of the Hubble constant at low redshift, the rate of acceleration since z=1, and the growth of large-scale structure. They also give an improved upper limit on the sum of the neutrino masses.
- April 5, 2012 | 12:00 PM | LASR Conference Room
WYSIWYG Space-Time
Albert Stebbins, Fermilab
Note: This was originally a Friday Seminar scheduled for April 6th. Due to a scheduling conflict, it will be held on Thursday, April 5th.
An observationally based, non-perturbative approach to learning about the space-time geometry of our universe.
On macroscopic scales new forces are determined by measuring accelerations e.g. Newton and Kepler for gravity, or balancing known with unknown forces in a static configuration. Dark energy is a putative gravitationally repulsive substance which permeates our universe, yet the evidence for it involves neither technique, but is rather a mix of observations and assumptions about the geometry of space-time and initial conditions. In fact much of cosmology is done this way. Here I examine what one can learn about space-time geometry purely by observations from a single vantage point of distant objects and their motions and, in particular, not assuming the cosmological principle. A formalism is developed whereby all of space-time geometry is expressed in terms of observables. Some new and interesting formulae are derived and a possible future path for dark energy studies is given.
- April 13, 2012 | 12:00 PM | LASR Conference Room
The rise of the red sequence: Exploring hierarchical growth with models and future prospects with the 3DHST and CANDELS surveys
Rosalind E Skelton, Yale University
A major merger observed with the 3D-HST survey.
The massive quiescent galaxies we see at low redshifts seem to evolve slowly and passively, having formed at high redshift. The role of mergers in their formation and growth is strongly debated, as there does not seem to be much room for growth based on the observed luminosity evolution. I will describe the simple models we have used to test how hierarchical growth affects red sequence galaxies from z=1 to z=0. We find that the changes in color and luminosity for a population that builds up through mergers are very similar to those of an old, passively evolving population, but imply very different mass growth. The observed evolution can be equally well explained as the result of hierarchical growth. I will discuss how the large new surveys 3DHST and CANDELS will extend our understanding of the role of mergers and the build up of bulges to lower masses and out to higher redshifts.
- April 20, 2012 | 12:00 PM | LASR Conference Room
First results from galaxy clustering in the BOSS survey
Will Percival, University of Portsmouth
First results from galaxy clustering in the BOSS survey
First results are presented from galaxy clustering measurements in the Baryon Oscillation Spectroscopic Survey (BOSS), which is part of SDSS-III. Data release 9, due for public release in July, contains 327,349 massive galaxies with an effective redshift z=0.57 covering 3,275 square degrees. Assuming a concordance LCDM cosmological model, this is equivalent to 0.77 h^{-3} Gpc^3, and represents the largest sample of the Universe ever surveyed at this density. I will present results including Baryon Acoustic Oscillation (BAO), Redshift-Space Distribution (RSD) measurements, and cosmological constraints from full fits to the clustering signal. In particular, including the BAO measurements alongside previous measurements, results in a BAO distance ladder, which will be compared to current supernovae measurements.
- April 27, 2012 | 12:00 PM | LASR Conference Room
New Cosmology from the South Pole Telescope
Oliver Zahn, University of California, Berkeley
I will talk about two ongoing cosmological revolutions that are fueled by high angular resolution and high sensitivity observations of the Cosmic Microwave Background: constraining the properties of the first sources of radiation in the universe via the kinetic Sunyaev-Zel'dovich effect, and constraining astroparticle and gravitational physics via lensing of the CMB. I will report on the status and prospects of these endeavors.
- May 4, 2012 | 12:00 PM | LASR Conference Room
DM-Ice: a Search for Dark Matter at the South Pole
Reina Maruyama, University of Wisconsin-Madison
DM-Ice: a Search for Dark Matter at the South Pole
I will describe DM-Ice, a proposed dark matter experiment at the South Pole. The aim of the experiment is to test the claim for an observation of dark matter by the DAMA collaboration by carrying out an experiment with the same detector technology, but in the southern hemisphere. By going to the opposite hemisphere, many of the suspected backgrounds would produce annual modulation with the opposite phase whereas the dark matter signature should stay the same. A 17-kg detector was installed in the Antarctic ice at the South Pole in December 2010 and is currently taking data. The full-scale experiment that can test DAMA's claim is currently being designed. I will report on the status of DMIce-17 and the plans for the full-scale experiment.
- May 11, 2012 | 12:00 PM | LASR Conference Room
ACTPol: A Polarized Receiver for the Atacama Cosmology Telescope
Laura Newburgh, Princeton University
ACTPol: A Polarized Receiver for the Atacama Cosmology Telescope
ACTPol is a ground-based experiment designed to measure the polarization of the Cosmic Microwave Background at arcminute scales. The ACTPol receiver will feature three independent arrays each with ~1000 polarization-sensitive feedhorn-coupled TES bolometers, giving a factor of ~4 improvement in sensitivity compared to the existing receiver for the 6m Atacama Cosmology Telescope (ACT). Our observation strategy will include survey regions chosen to overlap with other multi-frequency surveys. The resulting combination of sensitive maps enables a wide range of measurements and cosmological constraints including the spectrum from gravitational lensing, the sum of the neutrino masses, the number of relativistic species, the spectral shape of the primordial power spectrum, and the primordial helium abundance, along with many more. I will present an instrument overview, science goals, and the status of the first array, set to deploy this year.
- May 18, 2012 | 12:00 PM | KPTC 206 (Note Location)
The Acceleration and Escape of Particles in Young Supernova Remnants
Vikram V Dwarkadas, University of Chicago
The acceleration of high-energy particles to relativistic energies is
a long-standing problem that has been highlighted in recent times, with
the growth of various gamma-ray and cosmic ray facilities, and the
Fermi space telescope. Of particular importance are the properties of
the accelerator and their relation to the spectrum of accelerated
particles, and the energies to which particles are accelerated.
Combining numerical simulations of supernova remnant (SNR) evolution
with a solution of the cosmic-ray transport equation in test-particle
mode, we study the acceleration of particles at forward and reverse
shocks in both Type Ia and core-collapse SNRs. We include the effect
of various magnetic field profiles in the shocked interaction
region. We study the temporal evolution of the non-thermal particle
distribution, and synthesize surface brightness maps for various
radiation mechanisms. We investigate how the spectrum of escaped
particles depends on the time-dependent acceleration history in young
SNRs, and calculate the time-dependent gamma-ray spectra from
molecular clouds illuminated by the escaping cosmic-rays. We also
study the maximum energy of the escaped particles, and its evolution
with time, and provide analytic approximations for the same.
- May 25, 2012 | 12:00 PM | LASR Conference Room
Looking for cracks in the standard cosmological model: neutrinos and non-Gaussianity
Tristan L Smith, UC Berkeley
The cosmic microwave background (CMB) has provided us the laboratory in which we entered the era of 'precision cosmology'. By and large these observations have confirmed the basic, standard, cosmological model which supposes a universe seeded with Gaussian initial fluctuations and filled with non-relativistic matter, photons, and 3 neutrino species. As observations have become more
accurate it has become increasingly pertinent to test some of the assumptions that have gone into
building the standard cosmological model. In this talk I will present some of my recent work on testing
these assumptions.
First I will discuss how recent measurements of the small-scale CMB have hinted at the presence of
extra relativistic energy density within the universe. Any interpretation of these results will necessitate the measurement of some of the properties of any extra relativistic energy density. Using recent small-scale measurements of the CMB, along with my colleagues, we have been able to constrain the clustering properties of the extra relativistic energy density. We show that current observations disfavor the interpretation that any extra relativistic energy consists of standard neutrinos.
Second, there has been an increasing interest in testing whether the initial fluctuations follow Gaussian
statistics. These tests of 'primordial non-Gaussianity' use estimators constructed from either the CMB
three-point (bispectrum) or four-point (trispectrum) correlation functions. Usually an estimator constructed
from data is assumed to have a Gaussian probability distribution (PDF) as a result of the central limit theorem.
However, in this case the central limit theorem does not apply since the number of terms that appear in these
estimators are much greater than the number of measurements. A complete knowledge of the shape of the
PDF is necessary in order to properly assign confidence limits to any constraint. I will discuss how Monte Carlo
simulations show that the PDF for these estimators are highly non-Gaussian themselves, necessitating more
care in using these estimators, especially for future observations with the Planck satellite. I will also show how the constraining power of these estimators may be improved by using a realization-dependent normalization.
- June 8, 2012 | 12:00 PM | LASR Conference Room
TBA
Ivone Albuquerque, University of Sao Paulo
TBA
Thursday lunch discussions
Astronomy colloquia
- April 4, 2012 | 3:30 PM | BSLC 109
New Observational Handles on the Primordial Universe
Sarah Shandera, Pennsylvania State University
Note: Refreshments served at 3:15 pm
Early universe cosmology is entering a new phase thanks to more precise measurements constraining the primordial density inhomogeneities. The Planck satellite and current and near future Large Scale Structure surveys are pursuing statistics of the inhomogeneities beyond the well-measured power spectrum. The potential of these new statistics has changed the way we think about theories of the primordial universe, including inflation. I will present the current understanding of how new data may decode the particle physics of inflation and provide more compelling tests of the theoretical framework for the primordial universe.
- April 18, 2012 | 3:30 PM | BSLC 109
The Galaxy-Halo Connection Across Mass and Time
Risa Wechsler, KIPAC/Stanford University
Note: Refreshments served 3PM ~ TAAC 71
Dark matter halos are the fundamental building blocks in the growth of structure and they provide the framework for our modern understanding of galaxy formation. I will discuss the current state of the art in our understanding of the connection between galaxy properties and their dark matter hosts over a range of masses and redshifts. In the context of a given cosmological model, I will show how the galaxy-halo relation can be tightly constrained at low redshift, and how it can be used to infer the full star formation histories of galaxies. This model for the co-evolution of galaxies and LCDM halos is in excellent agreement with a wide range of data, including the evolution of the stellar mass function, galaxy clustering statistics, and the statistics of satellites around Milky Way mass hosts. I will discuss applications to several issues in cosmology, including modeling of the faintest dwarfs and extracting cosmological constraints from the largest galaxy surveys.
- May 2, 2012 | 3:30 PM | BSLC 109
Massive Gravity and Cosmology
Claudia de Rham, Case Western Reserve University
Note: Refreshments served 3PM ~ TAAC 71
Could the late-time acceleration of the Universe and the apparent discrepancy with standard particle physics be the first sign of the breakdown of gravity at very large distances? This is the question I will explore within the context of massive gravity. Whilst massive gravity is one of the earliest and most natural generalization of General Relativity, its fully consistent formulation was only unraveled recently. After discussing its realization I will explore its phenomenological implications, both on cosmological scales than within the solar system.
- May 16, 2012 | 3:30 PM | BSLC 109
Gravitational Lensing of the Cosmic Microwave Background
Gil Holder, McGill University
Note: Refreshments served 3PM ~ TAAC 71
Gravitational lensing of the temperature and polarization anisotropies of the CMB is rapidly emerging as a new cosmological tool. Current experiments (as an example, I will focus on the South Pole Telescope) are using this effect to make mass maps over large areas. The power spectra of these mass maps allow new constraints on cosmological parameters, while the maps themselves can be cross-correlated with other tracers of the mass distribution to better understand the connections between mass and light.
- May 30, 2012 | 3:30 PM | BSLC 109
TBA
Mike Gladders, The University of Chicago
Note: Refreshments served 3PM ~ TAAC 71
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Overview