Аннотация:

Cosmic strings have been actively studied over the past decades. They can be detected by their gravitational lensing as well as the wake effect. With the development of gravitational wave astronomy it becomes important to calculate the possible contribution of cosmic strings to the gravitational wave background. In most cases, only strings with nonzero rest mass are studied. However, null strings can also exist, moving at the speed of light and having a non-zero energy density. Such strings have both similar and different features compared to their massive counterparts. We study the interaction of null strings with massive objects such as rotating black holes, their emission of gravitational waves, and the possibility of obtaining information about the physics of the early Universe if such strings are discovered.