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I am a professor of physics in the Division of Physics, Mathematics, and Astronomy at Caltech.

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Research Interests:

What is the nature of the dark matter and dark energy that dominate the universe?  I am focused on efforts that try to better understand these mysterious components.  These efforts tend to have significant technology development aspects: one approach to understanding such elusive phenomena is to find ways to do new and better measurements.

Current Projects:

• Bolocam: a 144-element millimeter-wave camera for use on the Caltech Submillimeter Observatory.  We use Bolocam to look for high-redshift dusty galaxies (using the thermal emission for dust) and galaxy clusters (using the Sunyaev-Zeldovich effect) and to study well-known galaxy clusters in the SZ effect.  My primary interest is in the measurement of the abundance of galaxy clusters as a function of redshift, and correlation of SZ-flux-limited cluster surveys with optical and X-ray surveys, to better quantify the contribution and history of dark energy, and observations of well-known clusters in the SZ to better understand clusters and the systematics in SZ measurements.
  
  
• Participation in the Cryogenic Dark Matter Search II and SuperCDMS experiments, experiment that uses cryogenic detectors to search for rare interactions of WIMP dark matter with ordinary matter.  I did my thesis on CDMS I, the shallow-site pilot experiment.
  
  Want to see what our data look like?  See this YouTube realization.
  
  
• Development of Weakly-Interacting Massive Particle (WIMP) dark matter detectors using Microwave Kinetic Inductance Detectors (MKIDs) as phonon sensors.
  
  
• Development of a multi-band submm/mm-wave camera using MKIDs, MUSIC (MUlticolor Sub/millimeter Inductance Camera).  This will succeed Bolocam on the CSO and be a technology demonstrator for the CCAT long-wavelength camera.

Past Projects:

• CMB polarization work: involved early on in these projects, but have pulled out due to lack of time.  These are very much ongoing experiments.  Jamie Bock can serve as graduate advisor. SPIDER, a balloon-borne payload, and BICEP2/Keck Array, a ground-based receiver at the South Pole: experiments to search for the signature of inflationary gravity waves in the cosmic microwave background.

In the Works:

• Development of the SZ science case for and long-wavelength camera for the Cornell-Caltech Atacama Telescope, at 25-m submm and mm-wave telescope to be sited in the Atacama Desert, currently in the partnership development stage.
  
  
• Engineering work towards a ton-scale WIMP-search experiment using the CDMS technology, the Germanium Observatory for Dark Matter (GEODM).  See the talks below for details.

Opportunities

Grad students are welcome to contact me to discuss any of these projects and whether they might provide good thesis topics.

Undergrads: I only take on Caltech students for summer projects or academic year work.  I may not be able to respond immediately to your requests.

More information

Here are some recent talks, notes, papers, etc. to provide some more information on these projects.

• Lay audience talk on dark matter and dark energy (Caltech Seminar day, 2005): PDF.
  
  
• Bolocam
  
  • SZ anisotropy survey paper (Ap J 2009)
    
  • Jack Sayers PhD thesis (Dec 2007) on SZ anisotropy survey, including many additional analysis details:
  • Instrument description
  • Noise performance
  • Sky noise studies
  • Beam measurements, pointing reconstruction, flux calibration
  • Mapmaking and SZ anisotropy constraint technique
  • AzTEC (Bolocam II) instrument paper
    
  • Sky noise subtraction paper (Ap J 2010).
  • Pointed cluster study demonstration paper (5 clusters, Ap J 2011).  A longer paper on a sample of > 30 clusters is in prep (Czakon et al).
    
  • Talk on SZ survey results: PDF
  • More general talk on cluster astrophysics: PDF.
    
  
  
• MKID Camera
• LTD12 paper on DemoCam prototype
• LTD13 paper on MKID camera.
• See also the SPIE 2010 proceedings for a number of papers.
  
• Talk at FNAL on MKIDs for cosmology, including applications for MKID Camera and CMB polarization: PDF.
  
• See also above Bolocam talks
  
  
• CCAT (see the CCAT page for the full feasibility study report):
• SZ science:
• Section of the CCAT feasibility study report (Jan, 2006) on SZ science: PDF.
• An earlier, more detailed version: PDF.
  
• Technical note describing calculations for above document: PDF.
• AAS Jan 2008 poster on above: PDF.
  
• Instrumentation
• Section of the CCAT feasibility study report on LWCam: PDF.  
• AAS Jan 2008 poster on LWCam: PDF.
• Talk at 2011 Irvine FIR/Submm conference on CCAT instrumentation: PDF.
  


• Dark Matter
• CDMS 2008 results and MKID-based dark matter detector: PDF.
• CDMS 2008 results paper
• LTD12 paper on MKID-based WIMP dark matter detector design, LTD12 paper on MKID-based X-ray test devices.
• LTD13 paper on MKID-based X-ray test devices and injector devices.
• Talk on current status and future of CDMS/SuperCDMS/GEODM (Sep 2009): PDF.
• Review talk on dark matter searches (Aug 2009): PDF.
• Caltech PRC "Road to Zeptobarn Dark Matter" on current status of CDMS/SuperCDMS/GEODM, other direct detection searches (Feb 2010): PDF (24 MB!).
• Seminar talk on 2009/12 new results from CDMS II: PDF.
• Talk at FNAL on MKIDs for cosmology, including applications for dark matter detection: PDF.
  
  
• Assorted
• LTD7 paper on NIS tunnel junction noise, include electrothermal feedback.  The proceedings are not published, so this is the only place you'll find it!
• Introductory talk on noise theory relevant for mm-wave photon detection.
  

CV and publist (Dec 2009): PDF
More detailed summary of research activities (Dec 2009): PDF

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Teaching

Physics 106ab, classical mechanics.  (2004-05, 2005-06, 2006-07)
Physics 125ab, quantum mechanics.  (2007-2008, 2008-2009)
Physics 135c, experimental non-accelerator particle physics (2007)

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This page last updated 2011/06/21.