We present a cross-correlation analysis of the WMAP cosmic microwave background ( CMB ) temperature anisotropies and the SDSS galaxy density fluctuations .
We find significant detections of the angular CMB-galaxy correlation for both a flux limited galaxy sample ( z \sim 
0.3 ) and a high redshift ( z \sim 0.5 ) color selected sample .
The signal is compatible with that expected from the integrated Sachs-Wolfe ( ISW ) effect at large angles ( \theta > 4 ^ { \circ } ) and the Sunyaev-Zeldovich ( SZ ) effect at small scales ( \theta < 1 ^ { \circ } ) .
The detected correlation at low-z is in good agreement with a previous analysis using the APM survey ( z \sim 0.15 ) .
The combined analysis of all 3 samples yields a total significance better than 3 \sigma for the ISW and about 2.7 \sigma for the SZ , with a Compton parameter \overline { y } \simeq 10 ^ { -6 } .
For a given flat \Lambda CDM model , the ISW effect depends both on the value of \Omega _ { \Lambda } and the galaxy bias b .
To break this degeneracy , we estimate the bias using the ratio between the galaxy and mass auto-correlation functions in each sample .
With our bias estimation , all samples consistently favor a best fit dark-energy dominated model : \Omega _ { \Lambda } \simeq 0.8 , with a 2 \sigma error \Omega _ { \Lambda } = 0.69 - 0.86 .