BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:Scalarization of Bardeen spacetime
DTSTART;VALUE=DATE-TIME:20261107T090000Z
DTEND;VALUE=DATE-TIME:20261107T093000Z
DTSTAMP;VALUE=DATE-TIME:20261023T121216Z
UID:indico-contribution-2929@indico.itp.ac.cn
DESCRIPTION:Speakers: Long-Xing Huang (Lanzhou University)\nWe study the s
 calarization of the entire Bardeen spacetime which is constructed from a n
 onlinear magnetic monopole. For the pure Bardeen model\, it is well known 
 that there exist not only the general horizonless\, nonsingular Bardeen sp
 acetime solutions but also regular black hole (BH) solutions. When conside
 ring the Bardeen model coupled to a scalar field\, we find that under the 
 premise of solving throughout the entire spacetime (i.e.\, the radial coor
 dinate $r\\in[0\,\\infty)$ )\, there are two scenarios: one is the trivial
  pure Bardeen solution with a vanishing scalar field\, and the other is a 
 horizonless\, nonsingular scalarized Bardeen spacetime (SBS) solution. Dep
 ending on the value of the magnetic charge $q$\, these non-trivial solutio
 ns can be further divided into two categories: (1) When the magnetic charg
 e $q$ is below a certain critical value $q_c$ and the scalarization parame
 ter $a$ approaches the scalarization threshold $a_t$ from above (i.e.\, $a
 \\to a_t^+$)\, the scalar field vanishes\, and the spacetime reduces to th
 e horizonless\, nonsingular pure Bardeen spacetime. This behavior indicate
 s that this solution exhibits the general ``spontaneous" scalarization phe
 nomenon. (2) When $q \\geq q_c$\, in the limit $a \\to a_t^+$\, the scalar
  field is non-vanishing and the SBS approaches a ``frozen" SBS. Considerin
 g the importance of photon orbits in astronomical observations\, we analyz
 e the trajectories of photons around SBSs by analyzing null geodesics.\n\n
 https://indico.itp.ac.cn/event/417/contributions/2929/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2929/
END:VEVENT
END:VCALENDAR