2016-2017 SAMSI Program on �Sta$s$cal,Mathema$calandComputa$onalMethods

forAstronomy(ASTRO)

G. Jogesh Babu

Sta$s$calandAppliedMathema$calSciencesIns$tute

Whyastrosta$s$cs?Astronomersencounterasurprisingvarietyofsta$s$calproblemsintheirresearch:

–  Theskyhasvastnumbersofstars&galaxiesandgasonallscales.–  Moststarshaveorbi$ngplanets,mostgalaxieshaveamassiveblackhole–  Astronomersacquirehugedatasetsofimages,spectra&$meseriesof

planets,stars,galaxies,quasars,supernovae,etc.–  Variousproper$esofcosmicpopula$onsobservedandempiricallystudied

withallkindsoftelescopes(n>>p)–  Proper$esaremeasuredrepeatedlybutwithirregularspacing.–  Spa$aldistribu$onsinsky(2D),space(3D),andparameterspace(pD)is

complex(MVNassump$onusuallyinapplicable)EricFeigelsonandIstartedcollabora$nginlate1980sandtheterm`Astrosta$s$cs’wascoinedinmid1990s,whenwepublishedabookbythesamename.

Astrosta$s$csatSAMSIAstrostatistics Program at SAMSI January 2006�

•  Opening workshop January18-20,2006–  Bayesian astrostatistics–  Nonparametric inference–  Astronomy for Statisticians

•  Working groups –  Exoplanets, Surveys & Population studies–  Gravitational Lensing, –  Source detection & feature detection–  Particle Physics

•  Concluded with SCMA IV at Penn State in June 2006

Astrosta$s$csatSAMSIAstrostatistics sub Program Fall 2012

Statistical and Computational Methodology for Massive Datasets •  Workshop September19-21,2012–  Thesearchfortransients– Missions(Fermi,SDSS.DES,Plank,LSST,LIGO)–  Sparsity(high-dimensionaldata,butlow-dimsignal)–  DataMining

•  Working groups –  Discovery&Classifica$oninSynop$cSurveys;–  Inference&Simula$oninComplexModels,–  Stochas$cProcesses&AstrophysicalInference–  GraphicalModels&GraphicsProcessors

Astrosta$s$csatSAMSI

Exoplanets Summer 2013

ModernSta$s$calandComputa$onalMethodsforAnalysisofKeplerData

June10-28,2013

Astrosta$s$csatSAMSI

Sta4s4cal,Mathema4calandComputa4onalMethodsforAstronomy 2016-2017�

•  Opening workshop August22-26,2016–  TimeDomainAstronomy–  ExoplanetDataanalysis,HierarchicalModeling–  Uncer$nity,selec$oneffectsetc.,inGW–  PulsarTimingArraysandDetec$onofGWs–  Non-sta$onary,non-Gaussian,Irregularlysampledprocesses.–  Sta$s$alissuesinCosmology

SAMSIASTROProgramis$mely

•  Gravita$onalWavesDetected100yearsaeerEinstein’sPredic$on

•  FirstGW(GW150914)wasdetectedbyLaserInterferometerGravita$onal-WaveObservatory(LIGO)Confirmingamajorpredic$onofAlbertEinstein’s1915generaltheoryofrela$vity.(GWfromcollidingBlackHoles).

•  Theplanningmee$ngonSeptember21,2015includedLIGOscien$stswhohadonlyjustlearnedofthecandidatedetec$on,andhadtokeepitsecretun$lconfirmedandannouncedonFebruary11,2016.AsecondGWevent(GW151226)wasannouncedonJune15,2016.ItwasrecordedonDecember26,2015.

WorkingGroups

I.  UncertaintyQuan$fica$onandAstrophysicalEmula$on

II.  Synop$cTimeDomainSurveys

III.  Mul$variateandIrregularlySampledTimeSeries

IV.  AstrophysicalPopula$ons

V.  Sta$s$cs,computa$on,andmodelingincosmology

UncertaintyQuan$fica$onandAstrophysicalEmula$on

•  UncertaintyQuan$fica$on(UQ)andReducedOrderModeling(ROM)areatthecoreofmanyproblemsingravita$onandcosmology,fromdirectsimula$onsoftheEinsteinequa$onstotheinverseproblem(inferenceproblem).

•  Thegoalofthisworkinggroupistoleverageexper$sefromareassuchasgeneralizedpolynomialchaosandsimulatoremula$onbasedonstochas$cprocesses,anddomain-areassuchasgravita$on,astrophysics,andcosmology.GroupLeaders:DerekBingham(SimonFraser),EarlLawrence(LANL)

Synop$cTimeDomainSurveys•  TDAhasbeengekngricherintermsofdatasetsthatspanseveral

years,manybands,andincludedenseandsparselight-curvesforhundredsofmillionsofsources.

•  Thevariety,volumeetc.squarelyfallinBigDataregime.•  Thelight-curvesoeenhavelargegaps,areheteroskedas$c,and

theintrinsicvariability–oeenpoorlyunderstood–addsanelementofuncertaintywhenmul$-banddataarenotobtainedsimultaneously.–  Kepler-typeplanetsearch/characteriza$on(alsoinotherWGs)

–  binaryblack-holesearchesfromCRTTransientSurvey

GroupLeaders:AshishMahabal(Astro,Caltech),G.JogeshBabu(Stat,PSU)

AshishMahabalwilldiscusssomeoftheworkundervarioussubgroupsofthisWG.

Mul$variateandIrregularlySampledTimeSeries•  Ground-basedphotometricsurveys,withbillionsofirregularlightcurves,detectstellarvariabilityfromamul$tudeofsources,fromplanetarytransits,tosupernovae.Howdoweeffec$velyseparatetheseclassesinirregularlysampleddata?

•  Howcanwemaximizethesensi$vityofspace-basedphotometricsurveysfordetec$ngsmallplanetsinthepresenceofstellarac$vity?

•  Howcanwemeasureplanetmassesrobustlydespiteobserva$onaldatawithoutliers(duetostellarac$vityaffec$ngeitherDopplerdataortransit$mes)?GroupLeaders:BenFarr(Astro,U.Chicago),SoumenLahiri(Stat,NCSU)

Sta$s$cs,Computa$on,andModelingin

Cosmology•  Willbringtogetherleadingresearchersin

cosmology,computa$onalspa$alandBayesiansta$s$cs,experimentaldesign,andcomputermodelingtodevelopmethodologynecessaryforansweringfundamentalques$onsabouttheoriginandlargescalestructureoftheuniverse.

•  Howcanwemakeinferencesfordeterminis$cnonlineardynamicalsystems(inferenceofini$alcondi$onsandmodelparameters)?

GroupLeaders:JeffJewell(Astro,JPL),JoeGuinness(Stat,NCSU)

JeffJewellwilldiscusstheapplica4onsareasunderthisWG.

AstrophysicalPopula$ons•  Improvethesta$s$calmethodologyforinterpre$ngdetec$onsof

exoplanets,gravita$onalwaves(GW),aswellasusingthosetoinfertheunderlyingpopula$onofplanetarysystemsandGWsources.

•  Theexoplanetscommunityispar$cularlyinterestedindevelopingtechniquestorobustlydetectandcharacterizeplanetsinthepresenceofstellarac$vityfromDopplerSurveysforwhichwedonothaveafirstprinciplesmodel.

•  TheGWcommunityisinterestedindetec$nggravita$onalwavesourcesforwhichthedetailsoftheprimaryGWsignaland/orbackgroundsareunknown.

•  Bothapplica$onsrequiredevelopingalgorithmstoefficientlyexplorehigh-dimensionalparameterspacesandtoestablishconfidenceindetec$ons,despitecomplexandunknownsourcesofbackgroundsignalsthat“noise”.

GroupLeaders:JessiCisewski(Stat,Yale);EricFord(Astro,PennState)JessiCisewskiwillnowdiscusssomeoftheprogressmadeunderthisWG.