Is there physical content in D Branes?

[arivero]

I am having a hard time to see how/if D Branes are physics, at all.

We are told that it is the modern notation for Chan Paton charges. But then Marcus and Sagnotti, in the unique paper I have found on the topic, seem to think different

Reference
http://www.slac.stanford.edu/spires/find/hep/www?j=PHLTA,B188,58"
Neil Marcus (UC, Berkeley & LBL, Berkeley) , Augusto Sagnotti (Rome U.,Tor Vergata & INFN, Rome) . UCB-PTH-86/27, LBL-22076, ROM2F-86/015, Oct 1986. 10pp.
Published in Phys.Lett.B188:58,1987.

Is there any good work relating D-branes to "charges at the end of strings"?

 

[nrqed]

I am having a hard time to see how/if D Branes are physics, at all.

We are told that it is the modern notation for Chan Paton charges. But then Marcus and Sagnotti, in the unique paper I have found on the topic, seem to think different

Reference
http://www.slac.stanford.edu/spires/find/hep/www?j=PHLTA,B188,58"
Neil Marcus (UC, Berkeley & LBL, Berkeley) , Augusto Sagnotti (Rome U.,Tor Vergata & INFN, Rome) . UCB-PTH-86/27, LBL-22076, ROM2F-86/015, Oct 1986. 10pp.
Published in Phys.Lett.B188:58,1987.

Is there any good work relating D-branes to "charges at the end of strings"?

Are you specifically interested in string theory as applied to a theory of QCD or string theory in general (as a theory of everything)?

The need for branes in superstring theory goes beyond the introduction of gauge indices. I think that what Polchinski showed was that branes are required as elementary constituents in addition to strings. Introducing Chan-Paton factors at the end of open strings which end on branes can be done in order to introduce gauge groups but as far as I know, branes do not require Chan Paton factors (I mightbe wrong).

In any case, have you look at Zwiebach? He gives a nice introduction.

 

[Entropia]

I can assure you that D-branes are a well-established concept in physics and have been extensively studied and utilized in various areas of theoretical and experimental research. D-branes, also known as Dirichlet branes, are hypersurfaces on which open strings can end. They were first introduced in string theory as a way to incorporate boundary conditions for open strings. However, their significance goes far beyond that and they have been found to play crucial roles in various aspects of theoretical physics, such as black hole physics, gauge theories, and holography.

There is certainly physical content in D-branes. In fact, D-branes have been used to explain the origin of gauge theories, which are fundamental in describing the interactions between elementary particles. They have also been used to understand the dynamics of black holes, providing insights into the elusive quantum nature of gravity. Furthermore, D-branes have been extensively studied in the context of string dualities, which have revolutionized our understanding of the fundamental principles of physics.

The reference you have provided is a classic paper that discusses the relationship between D-branes and Chan-Paton charges. This is a fundamental aspect of D-brane physics and has been extensively studied and applied in various contexts. However, there have been numerous developments and advancements in the understanding of D-branes since this paper was published in 1987. I would suggest exploring more recent literature on the topic to gain a better understanding of the current state of research on D-branes.

Overall, D-branes are a crucial and well-established concept in modern physics, and their significance and physical content cannot be denied. They have been extensively studied and have provided key insights into many fundamental questions in physics. I would encourage you to continue exploring the topic and delving into more recent literature to gain a better understanding of the physical content of D-branes.