TY - JOUR

T1 - Light Like Segment Compactification and Braneworlds with Dynamical String Tension

AU - Guendelman, E. I.

N1 - Funding Information:
I thank Oleg Andreev, David Andriot, Stefano Ansoldi, David Benisty, Thomas Curtright, Euro Spallucci, Emil Nissimov, Svetlana Pacheva, Tatiana Vulfs, Hitoshi Nishino, Subhash Rajpoot, Luciano Rezzolla, Horst St?cker, Jurgen Struckmeier, David Vasak, Johannes Kirsch, Dirk Kehm, Luca Mezincescu and Matthias Hanauske for usefull discussions. I also want to thank the Foundational Questions Institute (FQXi) and the COST actions Quantum Gravity Phenomenology in the multi messenger approach, CA18108 and Gravitational waves, Black Holes and Fundamental Physics, CA16104 for support and special thanks to the Frankfurt Institute for Advanced Study for hospitality and finantial support and to Astrophysics Group at Goethe University for providing me with the opportunity of presenting these results in a seminar at one of their Astro Coffe Seminars, https://astro.uni-frankfurt.de/astrocoffee/ and to The University of Miami for the possibility of presenting these results at the Miami 2021 conference https://cgc.physics.miami.edu/Miami2021/.
Publisher Copyright:
© 2021, The Author(s).

PY - 2021/10/1

Y1 - 2021/10/1

N2 - There is great interest in the construction of brane worlds, where matter and gravity are forced to be effective only in a lower dimensional surface, the brane. How these could appear as a consequence of string theory is a crucial question and this has been widely discussed. Here we will examine a distinct scenario that appears in dynamical string tension theories and where string tension is positive between two surfaces separated by a short distance and at the two surfaces themselves the string tensions become infinite, therefore producing an effective confinement of the strings and therefore of all matter and gravity to the space between these to surfaces, which is in fact a new type of stringy brane world scenario. The specific model studied is in the context of the modified measure formulation the string where tension appear as an additional dynamical degree of freedom and these tensions are not universal, but rather each string generates its own tension, which can have a different value for each string. We consider a new background field that can couple to these strings, the tension scalar is capable then of changing locally along the world sheet and then the value of the tension of the extended object changes accordingly. When many types of strings probing the same region of space are considered this tension scalar is constrained by the requirement of quantum conformal invariance. For the case of two types of strings probing the same region of space with different dynamically generated tensions, there are two different metrics, associated to the different strings, that have to satisfy vacuum Einsteins equations and the consistency of these two Einsteins equations determine the tension scalar. The universal metric, common to both strings generically does not satisfy Einsteins equation. The two metrics considered here are flat space in Minkowshi space and flat space after a special conformal transformation and the tension field behaves in such a way that strings are confined inside a light like Segment or alternatively as expanding Braneworlds where the strings are confined between two expanding bubbles separated by a very small distance at large times.

AB - There is great interest in the construction of brane worlds, where matter and gravity are forced to be effective only in a lower dimensional surface, the brane. How these could appear as a consequence of string theory is a crucial question and this has been widely discussed. Here we will examine a distinct scenario that appears in dynamical string tension theories and where string tension is positive between two surfaces separated by a short distance and at the two surfaces themselves the string tensions become infinite, therefore producing an effective confinement of the strings and therefore of all matter and gravity to the space between these to surfaces, which is in fact a new type of stringy brane world scenario. The specific model studied is in the context of the modified measure formulation the string where tension appear as an additional dynamical degree of freedom and these tensions are not universal, but rather each string generates its own tension, which can have a different value for each string. We consider a new background field that can couple to these strings, the tension scalar is capable then of changing locally along the world sheet and then the value of the tension of the extended object changes accordingly. When many types of strings probing the same region of space are considered this tension scalar is constrained by the requirement of quantum conformal invariance. For the case of two types of strings probing the same region of space with different dynamically generated tensions, there are two different metrics, associated to the different strings, that have to satisfy vacuum Einsteins equations and the consistency of these two Einsteins equations determine the tension scalar. The universal metric, common to both strings generically does not satisfy Einsteins equation. The two metrics considered here are flat space in Minkowshi space and flat space after a special conformal transformation and the tension field behaves in such a way that strings are confined inside a light like Segment or alternatively as expanding Braneworlds where the strings are confined between two expanding bubbles separated by a very small distance at large times.

KW - hep-th

UR - http://www.scopus.com/inward/record.url?scp=85116699142&partnerID=8YFLogxK

U2 - 10.1140/epjc/s10052-021-09646-z

DO - 10.1140/epjc/s10052-021-09646-z

M3 - Article

SN - 1434-6044

VL - 81

JO - European Physical Journal C

JF - European Physical Journal C

IS - 10

M1 - 886

ER -