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Research Highlights |
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 CMB power spectrum (Guo-Chin Liu) | | |
| Observational constraints on dark energy (Hiroaki Nishioka) | | We have demonstrated that the quadrupole power spectrum will be the
powerful tool to constrain the nature of dark energy for the future galaxy redshift surveys.
The figure shows the likelihood contours in w-omega_m (w: dark energy equation of state parameter; omega_m: matter density parameter) plane obtained by the
Fisher matrix approach assuming the KAOS(Kilo Apperture Optical Spectrograph) sample. The medium large blue and the largest blue ellipses represent the constraints from monopole and quadrupole power spectrum, respectively. The combined constraint is shown in the darkest blue ellipse.
The use of the quarupole power spectrum significantly improves constraints on w and omega_m due to the Alcock-Paczynski effect.
Ref. Yamamoto, Bassett and Nishioka Phys.Rev.Lett. 94 (2005) 051301 | | |
| Gravitational lensing (Keiichi Umetsu) | | VRi' color image of the central 90" x 90" region of the high-z cluster RXJ0152 (z=0.83) obtained with Subaru/Suprime-Cam.
North is top and East is left. Also overlayed are the caustic (thick solid lines) and the critical curves (thin dashed lines) predicted by our best-fitting model.
The cross represents the predicted position of the source galaxy at z=3.9. The open squares represent the predicted positions of the multiple images I1, I2, and I3 (Umetsu et al. 2005, PASJ, 57, pp.877-880, 2005). | | |
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