Researchers Handhika Satrio Ramadhan, M Naufal Athaullah, and Ilham Prasetyo from the Department of Physics, Institut Teknologi Bandung, Indonesia, have revisited a complex theoretical physics problem with potential implications for our understanding of cosmic strings and their energy dynamics.
In their recent study, the researchers explored whether Dirac-Born-Infeld (DBI) cosmic strings can possess Bogomol’nyi-Prasad-Sommerfield (BPS) configurations, which are special states that minimize energy. Previous work by Babichev and colleagues concluded that DBI strings with standard potentials do not have BPS limits, implying that they always have some binding energy. However, Ramadhan, Athaullah, and Prasetyo used a different approach, the BPS Lagrangian method, to show that DBI strings can indeed admit BPS solutions, provided the potential is chosen carefully.
The researchers found that imposing the existence of Bogomol’nyi equations uniquely determines the allowable potential and yields exact first-order BPS equations for DBI vortices. They verified the consistency of these equations using the stressless condition on the energy-momentum tensor. The resulting solutions saturate the Bogomol’nyi bound, exhibit zero binding energy, and smoothly recover the Nielsen-Olesen string in the limit of small alpha (α). The regularity of the gauge-field equation requires that α is less than π squared.
A notable outcome of their construction is that the BPS-compatible potential takes a trigonometric form closely related to the sine-Gordon potential, revealing a natural correspondence between the sine-Gordon string and the BPS DBI string. The BPS tension scales linearly with the winding number but acquires an α-dependent deformation.
While this research is highly theoretical and abstract, it could have practical implications for the energy sector, particularly in understanding the fundamental properties of cosmic strings and their potential role in the universe’s energy dynamics. The study was published in the journal Physical Review D.
This article is based on research available at arXiv.