A scalar field with a pole in its kinetic term is often used to study cosmological inflation;it can also play the role of dark energy,which is called the pole dark energy model.We propose a generalized model where the...A scalar field with a pole in its kinetic term is often used to study cosmological inflation;it can also play the role of dark energy,which is called the pole dark energy model.We propose a generalized model where the scalar field may have two or even multiple poles in the kinetic term,and we call it the multi-pole dark energy.We find that the poles can place some restrictions on the values of the original scalar field with a non-canonical kinetic term.After the transformation to the canonical form,we get a flat potential for the transformed scalar field even if the original field has a steep one.The late-time evolution of the universe is obtained explicitly for the two pole model,while dynamical analysis is performed for the multiple pole model.We find that it does have a stable attractor solution,which corresponds to the universe dominated by the potential of the scalar field.展开更多
基金Supported by the NSF of China under Grant(11047138)"Chen Guang" project under Grant(12CG51)+1 种基金National Education Foundation of China under grant(2009312711004)Shanghai Natural Science Foundation under Grant(10ZR1422000)
基金Supported by National Science Foundation of China(11105091,11047138)"Chen Guang"project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation(12CG51)Shanghai Natural Science Foundation,China(10ZR1422000)。
文摘A scalar field with a pole in its kinetic term is often used to study cosmological inflation;it can also play the role of dark energy,which is called the pole dark energy model.We propose a generalized model where the scalar field may have two or even multiple poles in the kinetic term,and we call it the multi-pole dark energy.We find that the poles can place some restrictions on the values of the original scalar field with a non-canonical kinetic term.After the transformation to the canonical form,we get a flat potential for the transformed scalar field even if the original field has a steep one.The late-time evolution of the universe is obtained explicitly for the two pole model,while dynamical analysis is performed for the multiple pole model.We find that it does have a stable attractor solution,which corresponds to the universe dominated by the potential of the scalar field.
