We reconsider age problem in LCDM and find it suffer from age problem. We constrain the generalized tachyon field (GFT) and find GTF dark energy scenario is favored over the LCDM model. We perform phase-space analysis for k-essence model and point out it is important to investigate both the stability of the critical points and the stability of the model. We investigate the growth of the large-scale structure in the superfluid Chaplygin gas (SCG) model and find SCG cannot be discriminated from LCDM. We propose three types f(T) gravity and show that they all can give rise to cosmic acceleration. Conformal gravity are constrained and can accommodate the age of APM 08279+5255. Generalized Salecker-Wigner inequalities and modified black hole lifetime are obtained. We argued that thermal quantities,such as entropy, temperature, and chemical potential, can induce gravitational effects; and gravity can induce thermal effects.