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SUMMARY:[online] Meissner Effect and Kerr/CFT Holography of Extremal Kerr
 –Bertotti–Robinson Black Holes
DTSTART;VALUE=DATE-TIME:20261109T023000Z
DTEND;VALUE=DATE-TIME:20261109T030000Z
DTSTAMP;VALUE=DATE-TIME:20261023T153655Z
UID:indico-contribution-2940@indico.itp.ac.cn
DESCRIPTION:Speakers: Siahaan Haryanto Mangaratua (Parahyangan Catholic Un
 iversity)\nThe Kerr–Bertotti–Robinson (Kerr–BR) spacetime is a recen
 tly constructed exact Einstein–Maxwell solution describing a rotating bl
 ack hole immersed in a homogeneous Bertotti–Robinson electromagnetic uni
 verse. Unlike the familiar Melvin-type magnetized Kerr families\, its asym
 ptotics are AdS₂ × S²\, the external field explicitly deforms the hori
 zon and extremality condition\, and its Maxwell and Weyl principal null di
 rections are misaligned. In this talk I examine two complementary near-hor
 izon phenomena of the extremal Kerr–BR black hole and show that both are
  governed by the same Kerr/CFT data. First\, I establish the Meissner effe
 ct in a manifestly gauge-invariant way: the horizon-tangent field strength
  vanishes\, so the external magnetic flux is fully expelled\, while the re
 sidual gauge coefficient survives only as a local Wilson-line term. Second
 \, I derive the near-horizon Breitenlohner–Freedman instability criterio
 n for a charged scalar probe\, expressed through two gauge-invariant combi
 nations — the shifted fibre momentum and the effective Kaluza–Klein el
 ectric coupling. Both the Meissner expulsion and the BF threshold turn out
  to be controlled by the twist parameter and gauge coefficient that enter 
 the holographic dictionary\, revealing them as two probes of a single extr
 emal throat whose structure is fixed by the external field.\n\nhttps://ind
 ico.itp.ac.cn/event/417/contributions/2940/
LOCATION:
URL:https://indico.itp.ac.cn/event/417/contributions/2940/
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