https://doi.org/10.1140/epjc/s10052-009-0943-0
Regular Article - Theoretical Physics
A self-gravitating Dirac–Born–Infeld global monopole
Center for Astrophysics, Shanghai Normal University, 100 Guilin Road, Shanghai, 200234, China
* e-mail: djliu@shnu.edu.cn
Received:
15
December
2008
Revised:
6
January
2009
Published online:
26
February
2009
We generalize the field theory of the global monopole to the Dirac–Born–Infeld (DBI) field and investigate the gravitational property of a DBI global monopole in four-dimensional spherically symmetric spacetime. The coupled equations for the metric and the DBI scalar field are solved asymptotically and numerically. It is found that, just as for a canonical global monopole, the gravitational effect of the DBI global monopole is equivalent to that of a deficit solid angle in the metric plus a negative mass at the origin. However, compared with a canonical global monopole, for the same false vacuum and symmetry-breaking scale, a DBI global monopole has a relatively smaller core and a larger absolute value of effective mass. Thus, it can yield a larger deflect angle when the light is passing by. Especially, when the scale of the warp factor is small enough, the effective mass of a DBI global monopole does not depend apparently on the value of the false vacuum, which is qualitatively different from that of a canonical global monopole.
PACS: 11.27.+d –
© Springer-Verlag , 2009
