Strings with a different tension producing dark copies of the Standard Model

Abstract

This is a comment on our previous paper (Guendelman in Eur Phys J C 85(6). https://doi.org/10.1140/epjc/s10052-025-14408-2). The string and brane tensions do not have to be put in by hand, they can be dynamically generated, as in the case when we formulate string and brane theories in the modified measure formalism. Then string tension appears, but as an integration constant. It can be seen however that these string tensions are not universal, but rather each string and each brane generates its own tension. To make the string tension fully dynamical, a bulk field (the tension field) is introduced. As we have seen in previous publications, world sheet conformal invariance in the case of two different species of strings with different tension can produce braneworlds. Now we add another crucial observation; dark matter to us may consist of matter made out of strings with different tensions because of decoupling of standard string interactions for strings with different tensions, although interactions mediated by the tension field can exist between strings of different tensions. Furthermore, Visible Matter strings and these “dark strings” share the same space time, and therefore the same compactifications, etc. Since the choice of compactification organizes the structure of the theory including its particle content, we expect therefore that the dark sector will consist of dark copies of the standard model and a visible Matter Dark Matter correspondence could be established.