BCCP Seminars

Friday, October 31

INPA/Cosmology/BCCP
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.

Tuesday, November 4

Location: UCB, Hearst Field Annex B-1 – 1:10 pm
Speaker: Colin Slater, Michigan
Title: “Satellite quenching and the life cycle of dwarf galaxies”Abstract: In the past ten years the known population of Local Group dwarf galaxies has expanded substantially, both to greater distances from the Milky Way and to lower dwarf masses. This growing sample allows us to study the dwarf system as a population, and ask if we can see in aggregate the signs of processes that would otherwise be difficult to trace in dwarfs individually. Following this strategy I will discuss how the quenching of dwarf galaxies can be modeled and understood at the population-level, and how we use that to constrain how possible quenching mechanisms must work if they are to reproduce the Local Group system that we see. I will also discuss work done with Pan-STARRS to study the role of infalling satellites in disrupting the outer disk of the Milky Way and creating the so-called “Monoceros Ring”.

 

Visitors

 

Visitors Program

We maintain an active program for visiting scholars. BCCP hosts visitors at all levels, from senior scientists to postdocs, graduate students, and undergraduates. If you would like to visit BCCP, please fill out the form here.

Longer term visits involving collaborative activities with BCCP members are especially encouraged. BCCP can provide financial support for longer term visitors working with BCCP members on BCCP related projects. The applications are reviewed by a committee several times a year. All decisions are based on the availability of space and funding.

Fall 2014

  • Airam Marcos-Caballero (IFCA, Spain) – September 14-December 14
  • Miguel Zumalacárregui (University of Heidelberg) – September
  • Zvonimir Vlah (Univ of Zurich, ITP) – November 1-December 15

Summer 2014

  • Louis Garrigue (ENS-Ecole Normale Supérieure, Paris) – March 17-July 11
  • Jeremy Tinker (NYU) – June 17-August 21
  • Tamara Davis (U of Queensland) – June 24-27
  • Geraint Lewis (U of Sydney) – June 26-27

Spring 2014

  • Evan Scannapieco (ASU) – January 3-May 31
  • Irshad Mohammed (University of Zurich) – January 9-June 30
  • Miguel Zumalacárregui (University of Heidelberg) – January 22-February 10
  • Paul Shellard (University of Cambridge) – February 6-7
  • Arka Banerjee (University of Illinois, Urbana-Champaign) – February 9-22
  • Tong-Jie Zhang (Beijing Normal University) – February 27-May 27
  • Zvonimir Vlah (Univ of Zurich, ITP) – March 3-April 2
  • Louis Garrigue (ENS-Ecole Normale Supérieure, Paris) – March 17-July 11
  • Neal Dalal (Univ of Illinois) – March 26-28
  • Steffen Hess (AIP, Leibnitz Inst for Astrophysics, Potsdam) – May 12-22

Fall 2013

  • Elizabeth Krause (U Penn) – September 10-11
  • Zvonimir Vlah (Univ of Zurich, ITP) – September 17-December 20
  • Michael Kopp (LMU) – October 28-November 2
  • Juliana Kwan (Argonne National Lab) – November 13-22
  • Amol Upadhye (Argonne National Lab) – November 13-December 20
  • Teppei Okumura (IEU Korea) – November 13-30
  • Jonathan Blazek (OSU) – December 5-13

Summer 2013

  • Azadeh M. Dizgah (SUNY-Buffalo) – May 16-July 16
  • Jeremy Tinker (NYU) – May 30-August 20
  • Sudeep Das (Argonne National Lab) – July 9-27
  • Daniel Holz (Chicago) – August 27-28
  • Neal Dalal (Illinois) – August 30,
  • Wayne Hu (Chicago) – August 29-30
  • Joel Johansson (Stockholm) – August 29-30

Spring 2013

  • Alireza Hojjati (IEU Korea) – January 14-February 5
  • Chris Blake (Swinburne) – January 14-February 5
  • Tamara Davis (Queensland) – January 14-18
  • Morag Scrimgeour (Western Australia) – January 14 -
  • Sudeep Das (Argonne National Lab) – January 28-31
  • Chiaki Hikage (Nagoya University) – February 10-16
  • Miguel Zumalacarregui (Universidad Autonoma de Madrid) – February 15-22
  • Jaiyul Yoo (Univ. of Zurich) – February 23 – April 27
  • Laura Baudis (Univ. of Zurich) – April 26-May 4

Fall 2012

  • Stephen Appleby (IEU Korea) – October 7-26, 2012
  • Roland de Putter (Caltech/JPL) – October 19-25, 2012
  • David Pietrobon (JPL) – October 19-26, 2012
  • Tobias Baldauf (ITP, University of Zurich) – September 12-December 9, 2012
  • Johan Samsing (DARK Cosmology Centre, Copenhagen) – February-December 2012
  • Masanori Sato (Nagoya University, Japan) – October 5 – November 22, 2012
  • Andreu Font (University of Zurich) – November-December 2012
  • Teppei Okumura (Institute for the Early Universe, Seoul, Korea) – November 5-December 21, 2012

 

Events this week

Monday, October 27

Theoretical Astrophysics Seminars
Location: UCB – Hearst Field Annex B5, 12:10 p.m.
Speaker: Philipp Moesta (Caltech)
Title: “Magnetorotational Core-Collapse Supernovae in Three Dimensions”

4D Seminars
Location: UCB – 402 Old Le Conte, 2:30 p.m.
Speaker: Daniele Bertolini (UCB/LBNL)
Title: “Jets, Subjets, and Particles. Some New Tools for the LHC”

Physics Department Colloquium
Location: UCB, 1 Le Conte Hall – 4:15 p.m.
Speaker: Hartmut Haeffner (UCB)
Title: “Quantum information, decoherence-free subspaces, and a Michelson-Morley test with electrons”

Tuesday, October 28

Berkeley Cosmology Seminars
Location: UCB – Hearst Field Annex B1, 1:10 p.m. (also videoconferenced to LBNL 50-5026)
Speaker: 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.

String Seminar
Location: UCB – 402 Old Le Conte, 3:40 p.m.
Speaker: Joao Miguel Veira Gomes (DAMTP)
Title: “Quantum Supergravity and Exact Holography”

Physics RPM
Location:
LBNL – 50A-5132, 3 p.m. - Please note earlier time
Speaker:
Florencia Canelli (U. of Zurich)
Title:
“Searches for New Physics with Top Quarks”

Wednesday, October 29

BOSS Lunch
Location: LBNL – outside cafeteria

Special INPA Seminar
Location: LBNL, 50A-5132 – 2 p.m.
Speaker: Moshe Friedman (Hebrew University of Jerusalem)
Title: “Measurement of the Proton Form Factor Ratio at Low Momentum Transfer”
Abstract: The proton electric and magnetic form factors are basic characteristics of the proton, which can be associated with the Fourier transforms of the charge and magnetic current densities in the non-relativistic limit. QCD can make rigorous predictions when the four-momentum transfer squared, Q2, is very large, however, in the non-perturbative regime this task is too difficult, and several phenomenological models attempts to make predictions in this domain. Measurements of the proton form factors were traditionally based on cross section measurements and used the Rosenbluth separation to extract the electric and magnetic form factors. In this method, the magnetic form factor is suppressed as Q2 decreases, and precise data at very low Q2 is not available. In the last two decades, scattering experiments with polarized beams and targets have been used, and allow precise measurements of the proton form factors at much lower Q2. The second part of experiment E08-007 is attempting to measure the ratio between the proton form factors at 0.01 < Q2 < 0.08 GeV2, lower than ever achieved, by using the double-spin asymmetry technique. The experiment was conducted on spring 2012 at Hall A of the Thomas Jefferson National Accelerator Facility, using a 1-2 GeV polarized electron beam, scattering off a polarized solid ammonia target. Data analysis is currently in final stages. Recently, inconsistencies between different measurements of the proton radius have prompted intense theoretical and experimental activities to resolve the discrepancy. This experiment might improve our understanding of this problem. I will describe the experimental system, and show preliminary results for the asymmetries and expected uncertainties.

Particle Theory Seminar
Location: LBNL – 50A-5132, 2:00 p.m.
Speaker:  Gordan Krnjaic (Perimeter Institute)
Title: “Next Generation Beam Dump Experiments to Search for Light Dark Matter”

String Group Meeting
Location: UCB – 402 Old LeConte, 3:40 p.m.
Speaker: Stefan Leichenauer (UCB)
Title: “The Bayesian Second Law of Thermodynamics”

CANDi
Location: LBNL, 50-5026, 3:30 p.m.
Speaker: Davide Martizzi, http://arxiv.org/abs/1410.6826v1

Thursday, October 30

Astronomy Lunch
Location: UCB, B5 Hearst Field Annex – 12:30 p.m.
Speakers: *
Nathan Roth (UC Berkeley)  “Radiative transfer studies of tidal disruption events” / * Eve Lee (UC Berkeley)  “Make Super-Earths, Not Jupiters. / * Hilke Schlichting (MIT) “Atmospheric mass loss during planet formation: The importance of planetesimal impacts”

Physics Research Progress Meeting – no RPM today

Astronomy Colloquium
Location: UCB, 2 LeConte Hall, 4:00 p.m.
Speaker: Hilke Schlichting (MIT)
Title: “From Shocks to Resonances: Formation of Close-in Super-Earths and Mini-Neptunes”

Friday, October 31

INPA Seminar / Cosmology / BCCP
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.

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

Computing the Universe (CtU2015) Symposium & Cosmo Hack Week, Jan 12-16, 2015

 

From Jan 12-16, 2015 we will host our new annual “Computing the Universe” symposium and workshop, dedicated to bringing new solutions to some of the most pressing data analysis challenges in Cosmology and Computational Astrophysics.

 

The meeting will feature a hybrid format with updates on recent astrophysical data releases as well as cutting edge data science methods in the mornings, and “Cosmo Data Hacks” in the afternoons, where we will apply new methods and streamline existing ones to analyze these data sets in a highly hands-on fashion. 

Berkeley features mild weather with significant sunshine during January. There will be an excursion to the beach or to SF (in case of less than optimal weather).

There will be no registration fee and we will make reservations for housing at LBL guest house and nearby hotels. Registration will open Nov 1, 2014.

CtU2015CtU2015CtU2015

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: bccp.berkeley.edu.

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 https://aprecruit.berkeley.edu/apply/JPF00561 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 useljak@berkeley.edu, Oliver Zahn at zahn@berkeley.edu and Saul Perlmutter at saul@lbl.gov. For inquiries of administrative nature, contact Melissa Barclay at mbarclay@berkeley.edu.

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: http://apo.chance.berkeley.edu/evalltr.html.

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

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Cosmology Data-Science Fellow positions at all levels from post-doctoral through more senior scientist available in new “Cosmology Data Science Initiative” at Berkeley Center for Cosmological Physics

The Berkeley Center for Cosmological Physics (BCCP) at UC Berkeley is pioneering a new “Cosmology Data-Science Initiative,” with one or more positions available at all levels from post-doctoral through senior scientist, depending on experience. The members of this group will explore a novel approach to Cosmology Data Science (CDS): Each CDS Fellow will have half their research devoted to a specific cosmology project of the BCCP, working as a scientist in a research group with all of the expected goals of project planning, data collection, data reduction/analysis, publication, and conference-presentation of results. The other half of each CDS Fellow’s research will examine the data-science steps needed to accomplish these science goals, and look for approaches to redesigning these steps and make current and future science projects progress faster and more reliable. Questions that the CDS Initiative intends to address include: What are the current data science steps that are slowing down the scientists and/or distracting them from their primary science questions? What aspects make it difficult for a new member of a research team to come up to speed and begin contributing quickly? Why is it difficult to benefit from software that was written for a previous project, or by a previous member of the science team? For the data-science half of the CDS Fellow’s research, the Fellows will work not just individually, but also together as a CDS Initiative team, with the goal of finding or inventing common solutions to the problems and opportunities that they identify. The CDS team will also meet regularly with Data Science Fellows in other fields at UC Berkeley.

The CDS Fellows will have the opportunity to interact and work with the broad spectrum of cosmology researchers in the Berkeley Astronomy and Physics Departments, and at the Lawrence Berkeley National Laboratory (LBNL). The experimental and observational cosmology programs at Berkeley include supernovae, galaxy clustering (including baryonic acoustic oscillations), weak lensing and cosmic microwave background, in addition to a broad theoretical cosmology research program. Information on the BCCP’s current activities and membership may be found at the BCCP’s website: bccp.berkeley.edu. The Fellows will also find a rich data-science environment at UC Berkeley and LBNL, with world- expert researchers in both computer science and domain science aspects of this emerging field.

We plan to make one or more new Cosmology Data-Science Initiative Fellow appointments, in addition to the existing three. The positions are for two years initially with the possibility of extension of up to three additional years, subject to a performance review. Further extensions beyond this may be possible subject to availability of funds. Salaries for these full-time positions will be commensurate with experience.

Basic qualifications: Candidate must have completed all Ph.D (or equivalent) requirements in physics, astrophysics or a related field at the time of application (except for the dissertation or equivalent). Preferred qualifications: We are looking for individuals with strong scientific research experience, ideally in cosmology, as well as strong interest and experience in data science approaches. Additional qualifications: Must have received PhD or equivalent by start of appointment.

To apply, submit a copy of your curriculum vitae, bibliography, and statement of cosmology and data science research interests to: https://aprecruit.berkeley.edu/apply/JPF00562.  To receive full consideration please send the material by December 1, 2014, but later applications may also be considered until all the positions are filled.  At least 3 letters of reference should also be submitted by the same date.  For further inquiries, contact BCCP directors Uros Seljak at useljak@berkeley.edu, Oliver Zahn at zahn@berkeley.edu and Saul Perlmutter at saul@lbl.gov. For inquiries of an administrative nature, contact Melissa Barclay at mbarclay@berkeley.edu.

Salary and Benefits: Salary will be commensurate with experience. For information on UC Postdoc benefits, please visit: http://www.garnett-powers.com/postdoc/index.htm. UC Berkeley has an excellent benefits package as well as a number of policies and programs in place to support employees as they balance work and family. The Postdoctoral Scholar Benefits Plan (PSBP) provides a comprehensive program which offers Medical, Dental, Vision, Life and AD&D Insurance, Short-Term Disability Insurance and Voluntary Long- Term Disability Insurance. For a complete guide on UC Health Benefits for staff, please visit: http://ucnet.universityofcalifornia.edu/forms/pdf/complete-health-benefits-guide-for-employees.pdf