Wakefield Acceleration in the Universe

The important role of magnetic fields in the phenomena in and evolution of the Universe is well appreciated. A salient example of this is to make (often episodic) large magnetic fields in AGN accretion disks and their emanation of well-collimated and longitudinally extended astrophysical jets. Such typical cases or related astrophysical processes, we find, provide a fertile ground for exciting large-amplitude oscillations in the magnetic fields that constitute the spine of the jets. The energy sources of these oscillations can be traced originally to the gravitational energy of the central object. During their long propagation along the jet, because of the gradual changes of the density and magnetic fields, these large magnetic pulsations turn into relativistic amplitude electromagnetic (EM) pulses, which in turn induce intense wakefields that are capable of acceleration of electrons, positrons, and ions to high energies. In this review, we survey a variety of astrophysical objects ranging from as large as the cosmic AGN accretion disks and their jets to as small as microquasars, to find or predict that there exist common astrophysical processes of emission of high-energy particles and gamma (and other EM) emissions. A variety of these objects will be ideally observed and studied in the multimessenger astrophysical observations. One example that already stuck out was the case of the simultaneous observations of gravitational wave emission and gamma-ray pulse from the collision of the two neutron stars and their subsequent structure formation (such as a disk) around them.