*(under construction)*

*Supported by NASA through an Applied Information Research
grant NAG5-10750*

__Period:__

*04/15/01-04/14/02*

__Personnel:__

*Principal Investigator: Istvan Szapudi**Collaborators: Simon Prunet, Stephane Colombi (AIP, Paris)*

__Objectives:__

*The aim of this proposal is to develop an array**of techniques for statistical characterization**of the CMB based on fast clustering algorithms,**which will be used for estimation of the**angular power spectrum, polarization power**spectrum, cross correlations with large scale**structure and foregrounds, and constraining higher order**(non-Gaussian) statistics of the CMB.**The proposed novel methods enable the analysis of MAP**in minutes on a typical present day workstation,**allowing Monte Carlo studies hitherto impossible.*

__Status:__

*We have performed the basic algorithmic research underlying**the goals of our project. This resulted in new correlation
function engine,**SpICE, (Spatially Inhomogenous Correlation Estimator), which
can**produce correlation functions and the angular power spectrum**of the CMB in much shorter times then previously was possible.**For the first time, accurate analysis of megapixel CMB maps is**possible under very general assumptions on a simple workstation**(or even notebook).*

__Comparitive Timings:__

N | COBE | LDB | MAP | PLANCK |

Max Likelihood | 1 day | 1 year | 1600 years | 1.6 million years |

OSH | 80 hours | |||

Szapudi \etal (2001) | 0.08 sec | 85 sec | 23 hours | 96 days |

SpICE | 300sec | 46 minutes |

*In the above, Max Likelihood timings are estimated from Borill
(1999) and Bond, Jaffe \&**Knox (2000), OSH is the experiment specific technique of
Oh, Spergel \& Hinshaw.**The scaling is N^3, N^2, N^2, and N^1.6 for the four methods.*

__Publications:__

*The theory of the method is published in*

*Szapudi, Prunet,
Pogosyan, Bond, & Szalay (2001) ApJLett, 548, 11L.*

*The new algorithm and latest results for MAP simulations can be
found in*

*Szapudi, Prunet,
& Colombi (2001) ApJLett., 561,11L.*

__Preview:__

*Presently our team is working on incorporating our CMB analysis
software into the Planck
level 2 pipeline. We are also working on the public release of SpICE 1.0,
a HEALPix compatible**implementation of our algorithm with basic CMB analysis functionality.*

* Version 1.0 of
SpICE
is available now! Please read the README*

*spice -help*

*This version will calculate C_l's from CMB maps, with quite a
few options already**concerning noise, etc. Check it out!
(See also eSpICE)*