1. DARK ENERGY RICHARD BATTYE JODRELL BANK OBSERVATORY SCHOOL OF PHYSICS AND ASTRONOMY UNIVERSITY OF MANCHESTER PHENOMENOLOGY & PRESENT/FUTURE OBSERVATIONS

2. PLAN OF TALK DARK ENERGY PHENOMENOLOGY CURRENT OBSERVATIONAL STATUS FUTURE COSMOLOGICAL TESTS - REVIEW CLUSTER SURVEYS WITH THE SZ EFFECT EFECTS OF DARK ENERGY MODELS : THERE IS MORE TO LIFE THAN w ! LINEAR PERTURBATIONS CMB ALONE SNe ALONE CMB + 2dF + SNe WEAK LENSING (TALK BY ANDY TAYLOR) NUMBER COUNTS P(k,z) - BARYONIC OSCILLATIONS X-CORRELATION BETWEEN CMB AND LSS AN EXAMPLE OF NUMBER COUNTS EFFECT OF PERTURBATIONS WORK WITH ADAM MOSS WORK WITH JOCHEN WELLER

3. SNe Ia BASIC OBSERVATIONAL SITUATION CMB 2dF/SDSS TRIANGULAR ARGUMENT +

4. DARK ENERGY PHENOMENOLOGY

5. DARK ENERGY PRESSURE TO DENSITY RATIO : w=-1 COSMOLOGICAL CONSTANT SCALAR FIELDS : QUINTESSENCE TOPOLOGICAL DEFECT LATTICES MODIFICATIONS TO GRAVITY ? SUPER-HORIZON PERTURBATIONS ! COSMIC STRINGS : w=-1/3 DOMAIN WALLS : w=-2/3 EASY TO MODEL GIVEN A LAGRANGIAN MODELLED AS A RELATIVISTIC SOLID ie A FLUID WITH RIGIDITY ASSUME FLAT UNIVERSE NB POSSIBLE NON-MINIMAL COUPLING TO GRAVITY

6. TWO CLASSES OF TESTS GEOMETRICALGROWTH OF STRUCTURE ONLY DEPENDS ON w ! ANGULAR DIAMETER DISTANCE LUMINOSITY DISTANCE GROWTH DEPENDS ON w AND ALSO ON THE PROPERTIES OF THE DARK ENERGY LINEAR REGIME : NON-LINEAR REGIME : (i) MASS FUNCTION (ii) SPHERICAL COLLAPSE (*) OFTEN GEOMETRIC DEPENDENCE AS WELL

7. EXAMPLES OF GEOMETRICAL TESTS TYPE Ia SUPERNOVAEPEAK IN CMB POWER SPECTRUM degeneracydegeneracy (l>100)

8. GROWTH OF DENSITY PERTURBATIONS NEWTONIAN THEORY N-BODY SIMULATIONS (VIRGO COLLABORATION) GROWTH HALTS AT L DOMINATION

9. INTEGRATED SACHS-WOLFE EFFECT t rec t 0 PHOTON TRAJECTORY DF FOR STATIONARY POTENTIALS : GRAVITATIONAL POTENTIALS DECAY ONCE DARK ENERGY DOMINATES : THIS MODIFIES CMB POWER SPECTRUM AT LOW l BREAKS GEOMETRICAL DEGENERACY - BUT MODEL DEP

10. DIFFERENT MODELS FOR DE EQUATIONS OF MOTION FOR A GENERAL FLUID NON-ADIABATIC (SCALAR FIELD) ADIABATIC (SOLID) (Hu; Weller & Lewis; Bean & Dore) (Bucher & Spergel; Battye, Bucher & Spergel)

11. LOW l CMB POWER SPECTRUM SCALAR FIELD SOLID W=-1/3 W=-2/3W=-4/3  CDM

12. PRESENT OBSERVATIONAL STATUS

13. CMB DATA ALONE BEST FIT MODELS ISOTROPIC SOLID DARK ENERGY NO PERTURBATIONS IN DE SCALAR FIELD DARK ENERGY THIS ANALYSIS FAVOURS w=-1/3 COSMIC STRING MODELS

14. SUPERNOVA DATA

15. CMB + 2dF + SNe SCALAR FIELD DARK ENERGY NO PERTURBATIONS ISOTROPIC SOLID DARK ENERGY NB : CMB ALMOST BURNT OUT IN TERMS OF DE, BUT ~2000 SNe CAN BE JDEM AND OTHERS MESSAGE : TAKE CARE WITH w !

16. FUTURE OBSERVATIONAL TESTS

17. NUMBER COUNTS EXAMPLES : RADIO SOURCES GRAVITATIONAL LENSES CLUSTERS (X-RAY, SZ, REDSHIFT SURVEYS) SKY COVERAGE SELECTION FUNCTION : FLUX LIMITED COMOVING NUMBER DENSITY - EVOLUTION

18. NUMBER COUNTS : CLUSTERS 1 per 200 deg 1 per 2 deg 10 per 1 deg 2 2 2

19. DEPENDENCE ON COSMOLOGY LCDM  w=-0.8+0.3z s= 0.72 8

20. SURVEY YIELD CALCULABLE TOTAL NUMBER OF OBJECTS LARGE REDSHIFT DEPENDENCE NOISE RATHER THAN CONFUSION DOMINATED CONTROL OF SYSTEMATICS NUMBER COUNTS : IMPORTANT FEATURES ACCURATE CORRELATION BETWEEN MASS AND PROXY (EG FLUX) POISSON ERRORS SEPARATE OPTICAL SURVEY? NEED TO AVOID CONTAMINATION IS THE MASS PROXY UNBIASED ?

21. BARYONIC OSCILLATIONS z=500 z=100 z=0 BARYONSCDM OSCILLATIONS TRANSFERRED FROM BARYONS TO CDM ( EISENSTEIN 2003) z=20

22. DEPENDENCE ON PARAMETERS w=-1/3 w=-2/3 w=-1 PLOTTED RELATIVE TO ZERO BARYONS BREAKS GEOMETRICAL DEGENERACY NON-LINEAR SCALE SMALLER AT HIGH z REQUIRES UNDERSTANDING OF BIAS

23. BARYONIC OSCILLATIONS : STATUS EFFECT DETECTED IN (i) SDSS LUMINOUS RED GALAXY SURVEY (ii) 2dF (Cole et al 2005) (EISENSTEIN et al astro-ph 2005)

24. X-CORRELATION : LSS & CMB ISW EFFECT LARGE-SCALE STRUCTURE bias selection function =0 for matter dominated universes CROSS-CORRELATE WHERE SENSITIVE TO ISW AND HENCE PERTURBATIONS IN DE COULD BE USED TO DISTINGUISH DE MODELS (CRITTENDEN & TUROK 1996)

25. X-CORRELATION : STATUS XRB CROSS CORRELATION (Boughn & Crittenden, Nature 2004) X-ray Background 2.4-2.8s(Boughn & Crittenden) NVSS (Radio) 1.8-2.3s(Boughn & Crittenden) 2MASS (Infra-red) 2.5s(Afshordi, Loh & Strauss) SDSS (Optical) 90-95% confidence (Scranton et al)  CDM prediction  m

26. FUTURE REDSHIFT SURVEYS LARGE NUMBER OF OBJECTS LARGE COSMOLOGICAL VOLUME ACCURATE REDSHIFTS BIAS - WHAT IF IS SCALE DEPENDENT? PLANNED SURVEYS - AN INCOMPLETE LIST POISSON ERRORS ARE DOMINANT SOURCE OF ERRORS WIDE AREA DEEP SURVEYS PHOTOMETRIC V SPECTRSCOPIC Dark Energy SurveyOPT10^8 gal to z~1PHOTO-z 2009 DarkCam on VISTAOPT/IR "PHOTO-z 2009 KAOSOPTout to z~3.5!SPEC-z 2012 LSST OPT PHOTO-z2012 SKARADIO10^9 gal to z~1.5 SPEC-z2015

27. CLUSTER SURVEYS USING THE SZ EFFECT

28. THERMAL SUNYAEV-ZELDOVICH EFFECT  T INDEPENDENT OF z :

29. QUANTIFYING THE THERMAL SZ EFFECT x = f/56.4GHz

30. TARGETED OBSERVATIONS RYLE TELESCOPE VERY SMALL ARRAY (Lancaster et al 2004)

31. 1ST GENERATION INSTRUMENTS ~ 50deg 8x3.5m ANTENNAE OWENS VALLEY, CA =30GHz & 90GHz LINK WITH CARMA 10x3.7m ANTENNAE CAMBRIDGE =15GHz Tsys=25K,  =6GHz RYLE TELESCOPE AMI SZA 2 - INTERFEROMETERS

32. 2ND GENERATION INSTRUMENTS -LARGE AREA OR VERY DEEP SURVEYS GROUND BASED : SPT, ACT, APEX-SZ SPACE MISSIONS : PLANCK MULTI-ELEMENT FOCAL PLANE ARRAYS HIGH RESOLUTION ~1', 100-5000 deg BOLOMETERS ~150GHz TOTAL POWER -NEED A DRY SITE ~1000-10000 CLUSTERS MULTI-FREQUENCY 30GHz-850GHz LOW RESOLUTION ~5'-10' POWERFUL REJECTION OF SYSTEMATICS ALL-SKY ~5000-10000 NEARBY CLUSTERS 2

33. INPUT PHYSICS : SIMPLE MODEL e e e e e e e e e e SPHERICAL AND VIRIALIZED ISOTHERMAL DISTRIBUTION IN M & z GAS PROFILE SPHERICAL COLLAPSE NUMERICAL SIMULATIONS CORE RADIUS VIRIAL RADIUS

34. COMPUTING THE SELECTION FUNCTION MAXIMAL 8' 4' 2' 1' 16'

35. COSMOLOGICAL DEPENDENCE DIFFERENCE BETWEEN L AND w=-0.8+0.3z FOR 1 sq. deg AT LEAST 750 sq deg NEEDED

36. SPT PLANCK SIMULATED DATA AMI/SZA

37. SIMULATED CONSTRAINTS CENTRAL CONTOUR CORRESPONDS TO SPT FIDUCIAL MODEL: w=-0.8+0.3z

38. COMPLEMENTARITY TO SNe Ia SNe SZ

39. +16% -12% MASS-TEMPERATURE RELATION

40. CONCLUSIONS DARK ENERGY APPEARS TO EXIST GOOD MICROSCOPIC MODELS SCARCE PHENOMOLOGICAL DESCRIPTION REQUIRED IN PRINCIPLE MANY WAYS TO TEST IT MANY SYSTEMATIC ISSUES TO BE ADDRESSED VARIATION IN w DIFFICULT DARK ENERGY EXPERIMENTS COST ~ 10 MILLION £/$/EUROS