Computing the Universe symposium and cosmology hack week

CtU2015CtU2015 CtU2015 CtU2015

BCCP Job Opportunities

Postdoctoral Fellow positions

The Berkeley Center for Cosmological Physics (BCCP) at the University of California, Berkeley, invites applications for the BCCP Postdoctoral Fellowship, starting in the summer or fall of 2015. The BCCP Fellows are expected to carry out independent research on topics of their choosing in cosmology. We are especially encouraging applications in the intersection area between cosmology, fundamental physics and astrophysics. The position is for three years. In addition to being considered for the BCCP Fellowship, applicants will also be considered for grant-supported postdoctoral positions with BCCP members. Information on the BCCP’s current activities and membership may be found at the BCCP’s website:

Successful candidates will have the opportunity to interact and work with the broad spectrum of researchers in the Berkeley Astronomy and Physics Departments, and at the Lawrence Berkeley National Laboratory. The experimental and theoretical cosmology programs at Berkeley include supernovae, galaxy clustering, weak lensing and CMB.

Candidates should have obtained their Ph.D. in physics, astrophysics or a related field before their appointment start date. The total duration of an individual’s postdoctoral service may not exceed five years, including postdoctoral service at other institutions.

To apply, submit a copy of your curriculum vitae, bibliography, and statement of research interests to by December 1, 2014. At least 3 letters of reference should also be submitted by the same date.    For further inquiries contact BCCP directors Uros Seljak at, Oliver Zahn at and Saul Perlmutter at For inquiries of administrative nature, contact Melissa Barclay at

All letters will be treated as confidential per University of California policy and California state law. Please refer potential referees, including when letters are provided via a third party (i.e., dossier service or career center), to the UC Berkeley statement of confidentiality:

UC Berkeley is an equal opportunity/affirmative action employer. Benefits are included.




Executive Director
Oliver Zahn


Uros Seljak

Saul Perlmutter, Nobel Laureate

Founding Director
George Smoot, Nobel Laureate

Current BCCP-affiliated Postdocs

Florian Beutler

Andreu Font

Brian Hayden

Adrian Liu

Michael Mortonson

Claire Poppett

Marcel Schmittfull

Blake Sherwin

Marcel van Daalen

BCCP-affiliated graduate and undergraduate students

Nick Hand

Casey Stark

Erik Aldape


Cosmology Data Science (CDS) Fellows
Beth Reid

Kyle Barbary

Yu Feng

Other BCCP-affiliated faculty and LBL scientists

Greg Aldering

Steven Bailey

Chris Bebek

Julian Borrill

Joanne Cohn

Bob Cahn

William Holzapfel

Alex Kim

Adrian Lee

Michael Levi

Eric Linder

Pat McDonald

Peter Nugent

Natalie Roe

David Schlegel

Rollin Tomas

Martin White


Former BCCP Postdocs
Sudeep Das

Hee-Jong Seo

Anze Slosar

Tristan Smith

Jeremy Tinker

System Admin

Bryan Abshier

Events this week

Monday, October 20

Theoretical Astrophysics Seminars
Location: UCB – Hearst Field Annex B5, 12:10 p.m.
Speaker: Matteo Cantiello (KITP)
Title: “The Physics of Stellar Angular Momentum Transport”

Special INPA Seminar
Location: LBNL – INPA Common Room (50-5026), 12:00 p.m.
Speaker:  Joulien Tatar (U. of Washington & UC-Irvine)
Title:  “Toward Completion of the Hexagonal Prototype Antarctic Ross Ice-shelf ANtenna Neutrino Array (ARIANNA)
Abstract: ARIANNA aims to push the boundaries of extremely high energy neutrino physics, by achieving at least an orders of magnitude better sensitivity to extragalactic neutrinos with energies between 10^17 and 10^20 eV relative to any other experiment to date.
ARIANNA is a surface array detector. The full array will span ~1300 km^2 of the vast Ross Ice Shelf (RIS), and have a ~0.7 teraton fiducial volume. ARIANNA uses a unique method to monitor such a vast area. It listens for sub-nanosecond radio frequency pulses, reflected off the water-ice interface at the bottom of the RIS, which reach the surface. The viability of the detection technique has been confirmed.
The experiment is currently in its R&D stage with the goal of successfully running seven stations in a hexagonal array configuration. Three second generation stations have been deployed and operated during the 2013-2014 season, collecting excellent quality data that are indicative of the performance and capability of a full array. The final four stations will be deployed in a few months, completing the demonstration phase of the experiment.

4D Seminars
Location: UCB – 402 Old Le Conte, 2:30 p.m.
Speaker: Yue Zhao (Stanford)
Title: “Explicitly Broken Supersymmetry with Exactly Massless Moduli”

RAL seminar
Location: UCB,  Hearst Field Annex B1, 3:10 p.m.
Speaker: Tabitha Voytek (Carnegie Mellon University)
Title: Hydrogen and the First Stars: First Results from the SCI-HI 21-cm all-sky spectrum experiment
Abstract: I will be introducing the 
Sonda Cosmologica de las Islas para la Deteccion de Hidrogeno Neutro” (SCI-HI) experiment. This experiment is an all-sky 21-cm brightness temperature spectrum experiment studying the cosmic dawn (z~15-35) through the temporal evolution of the IGM. The experiment is a collaboration between Carnegie Mellon University (CMU) and Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE) in Mexico. Initial deployment of the SCI-HI experiment occurred in June 2013 on Guadalupe; a small island about 250 km off of the Pacific coast of Baja California in Mexico. I will discuss the preliminary measurements from this deployment, placing first constraints on the 21-cm all-sky spectrum around 70 MHz (z~20), see Voytek et al (2014). I will also discuss the current work to improve the experiment; including both instrumental improvements and deployment locations.

Physics Department Colloquium
Location: UCB, 1 Le Conte Hall – 4:15 p.m.
Speaker: Eddie Farhi (MIT)
Title: “Physics Based Approaches to Quantum Computing”

Tuesday, October 21

Berkeley Cosmology Seminars
Location: UCB – Hearst Field Annex B1, 1:10 p.m. (also videoconferenced to LBNL 50-5026)
Speaker: Josh Dillon, MIT
Title: “Chasing the Cosmic Dawn with 21 cm Tomography”
Abstract: Realizing the promise of 21 cm cosmology to provide an exquisite probe of astrophysics and cosmology during the cosmic dark ages and the epoch of reionization has proven extremely challenging. We’re looking for a small signal buried under foregrounds orders of magnitude stronger. We know that we’re going to need very sensitive, and thus very large, low frequency interferometers, which present their own set of difficulties. And, as I will explain, we’re going to need a rigorous statistical analysis of the maps we make to extract interesting cosmological information. I will discuss the steps we’ve taken to overcome these obstacles with prototype data from the Murchison Widefield Array by isolating foregrounds to a region of Fourier space outside a clean “epoch of reionization window.” Additionally, I will present some of most recent and exciting predictions for what 21 cm cosmology can tell us as we move to larger telescopes like the Hydrogen Epoch of Reionization Array and higher redshifts.

String Seminar
Location: UCB – 402 Old Le Conte, 3:40 p.m.
Speaker: Brian Swingle (Stanford)
Title: “The Information Theoretic Interpretation of the Length of a Curve”

Physics RPM – no RPM today

Wednesday, October 22

BOSS Lunch
Location: LBNL – 50B-4205; featuring Nikhil Padmanabhan

Particle Theory Seminar
Location: LBNL – 50A-5132, 2:00 p.m.
Speaker:  Ken Van Tilburg (Stanford)
Title: “Searching for Dilaton Dark Matter with Atomic Clocks”

String Group Meeting
Location: UCB – 402 Old LeConte, 3:40 p.m.
Speaker: Thomas Bachlechner (Cornell)
Title: “Naturally Aligned Chaotic Inflation”

CANDi – not meeting today

Thursday, October 23

Astronomy Lunch
Location: UCB, B5 Hearst Field Annex – 12:30 p.m.
Speakers: *
Melissa Graham (UC Berkeley) “SN2014J with APF” / * Daniel Lecoanet (UC Berkeley)  “Dedalus: A Flexible, Open-Source PDE Solver” / * Eve Ostriker (Princeton)  “Formation of magnetized prestellar cores”

Physics Research Progress Meeting – no RPM today

Astronomy Colloquium
Location: UCB, 2 LeConte Hall, 4:10 p.m.
Speaker: Eve Ostriker (Princeton)
Title: “Opulence and Thrift in the Interstellar Medium”

Abstract: Star formation governs many aspects of galactic structure and evolution, but it is even move intimately linked to the structure and evolution of the interstellar medium (ISM). The rate of star formation determines the rate at which gas is locked into orbit within a galactic halo, and (together with galactic winds) determines the depletion of a galaxy’s store of baryons. In disk galaxies, star formation is often characterized as being “inefficient” because only a tiny fraction of the gas store is depleted per dynamical time. However, in addition to removing gas from the ISM, star formation injects tremendous amounts of energy, through the radiation, winds, and supernova explosions associated with short-lived massive stars. This feedback is crucial for heating and driving turbulence in the ISM, and therefore for setting the ISM’s thermal and turbulent pressure. Intriguingly, it can be shown that in a wide range of systems, from outer galaxies to ULIRGs, the rate of star formation is just what is required to maintain vertical dynamical equilibrium in the ISM disk. Thus, star formation — as observed in “Kennicutt-Schmidt” and similar empirical relations — is regulated by demand (of energy and momentum) rather than supply (of gas mass). In this talk, I will outline the simple principles of self-regulated star formation, and present results of numerical simulations that support and calibrate the theory. Along the way, I will show that the momentum injection from expanding core-collapse supernova remnants is a key parameter in controlling star formation, and that this parameter is remarkably insensitive to the ambient properties of interstellar gas.

Friday, October 24

INPA Seminar
Location: LBNL, 50-5026, 12 p.m.
Speaker: Joulien Tatar (U. of Washington & UC-Irvine)

Title: “Toward Completion of the Hexagonal Prototype Antarctic Ross Ice-shelf ANtenna Neutrino Array [ARIANNA]“
Abstract:  tba

SSL Colloquium
Location: SSL Addition Conference Room (#105) – 3:00 p.m.
Speaker: tba
Title: tba

BCCP Seminars

Tuesday, October 28

Location: UCB,
Hearst Field Annex B-1, 1:10 p.m.
Joseph Clampitt, Penn
Title: “Lensing Measurements of SDSS Voids and Filaments”Abstract: I will describe measurements of weak lensing mass profiles of voids from a volume-limited sample of SDSS Luminous Red Galaxies (LRGs). The stacked shear measurement has been performed on ~10,000 voids and subvoids with radii between 15-40 Mpc/h and redshifts between 0.16-0.37. The characteristic radial shear signal of voids is detected with a statistical significance that exceeds 13-sigma. The mass profile corresponds to a fractional underdensity of about -0.4 inside the void radius and a slow approach to the mean density indicating a partially compensated void structure. Time permitting, I will also describe a stacked weak lensing detection of filaments between close pairs of LRGs.

Friday, October 31

Location: LBNL,
50-5026, 12 p.m.
Speaker: Liang Dai, JHU
Title: “Conformal Fermi coordinates and the local universe formalism”Abstract: In an inhomogeneous Universe, the physical effect of long-wavelength perturbation on short distances should be such that short-wavelength perturbations effectively evolve in a modified homogeneous universe. We explicitly construct the so-called conformal Fermi normal coordinates (CFNC) through an expansion around the observer’s geodesic, which describe the local spacetime as a quasi-FRW metric and are valid at all times. The CFNC formalism demonstrates that the zeroth-order picture is that local expansion rate and spatial curvature are renormalized by long-wavelength perturbations, and the general condition for the spatial curvature to be a constant is derived. Beyond this “separate universe” picture, CFNC allows for systematic extraction of additional local effects from long-wavelength perturbations that cannot be attributed to a re-definition of the background FRW cosmology. The formalism can be useful in the studies of tracer bias, intrinsic alignment and gravitational-wave “fossil” effect.