TY - JOUR T1 - Quantum Cherenkov Radiation and Non-contact Friction JF - Physical Review A Y1 - 2013 A1 - Mohammad F. Maghrebi A1 - Ramin Golestanian A1 - Mehran Kardar AB - We present a number of arguments to demonstrate that a quantum analog of Cherenkov effect occurs when two dispersive objects are in relative motion. Specifically we show that two semi-infinite plates experience friction beyond a threshold velocity which, in their center-of-mass frame, is the phase speed of light within their medium. The loss in mechanical energy is radiated away through the plates before getting fully absorbed in the form of heat. By deriving various correlation functions inside and outside the two plates, we explicitly compute the radiation, and discuss its dependence on the reference frame. VL - 88 UR - http://arxiv.org/abs/1304.4909v2 CP - 4 J1 - Phys. Rev. A U5 - 10.1103/PhysRevA.88.042509 ER - TY - JOUR T1 - A Scattering Approach to the Dynamical Casimir Effect JF - Physical Review D Y1 - 2013 A1 - Mohammad F. Maghrebi A1 - Ramin Golestanian A1 - Mehran Kardar AB - We develop a unified scattering approach to dynamical Casimir problems which can be applied to both accelerating boundaries, as well as dispersive objects in relative motion. A general (trace) formula is derived for the radiation from accelerating boundaries. Applications are provided for objects with different shapes in various dimensions, and undergoing rotational or linear motion. Within this framework, photon generation is discussed in the context of a modulated optical mirror. For dispersive objects, we find general results solely in terms of the scattering matrix. Specifically, we discuss the vacuum friction on a rotating object, and the friction on an atom moving parallel to a surface. VL - 87 UR - http://arxiv.org/abs/1210.1842v2 CP - 2 J1 - Phys. Rev. D U5 - 10.1103/PhysRevD.87.025016 ER -