The feasibility of constraining dark energy using LAMOST redshift survey

We consider using future redshift surveys with the Large Sky Area MultiObject Fiber Spectroscopic Telescope (LAMOST) to constrain the equation of state of dark energy omega. We analyze the Alcock & Paczynski (AP) effect imprinted on the two-point correlation function of galaxies in redshift space. The Fisher matrix analysis is applied to estimate the expected error bounds of omega(0) and omega(a) from galaxy redshift surveys, omega(0) and omega(a) being the two parameters in the equation of state parametrization omega(z) = omega(0) + omega(a)z/(1 + z). Strong degeneracies between omega(0) and omega(a) are found. The direction of the degeneracy in omega(0) - omega(a) plane, however, rotates counter-clockwise as the redshift increases. LAMOST can potentially contribute in the redshift range up to 0.5. In combination with other high redshift surveys, such as the proposed Kilo-Aperture Optical Spectrograph project (KAOS), the joint constraint derived from galaxy surveys at different redshift ranges is likely to efficiently break the degeneracy of omega(0) and omega(a). We do not anticipate that the nature of dark energy can be well constrained with LAMOST alone, but it may help to reduce the error bounds expected from other observations, such as the Supernova/Acceleration Probe (SNAP).