TY - JOUR
T1 - Gravitational waves from ultracompact stars
T2 - the optical geometry view of trapped modes
AU - Abramowicz, Marek A.
AU - Andersson, Nils
AU - Bruni, Marco
AU - Ghosh, Pranab
AU - Sonego, Sebastiano
PY - 1997/12/1
Y1 - 1997/12/1
N2 - Ultracompact stars - if they exist - have a unique signature: a discrete spectrum of slowly damped gravitational-wave quasinormal modes. It is known that this feature is due to a potential well present for stars with R < 3M. In this letter we show that the appearance of this well is essentially due to the non-Newtonian behaviour of the centrifugal potential: here we explain this behaviour adopting the optical geometry point of view. This insight leads us to an approximation, valid for highly compact stars, by which the real part of the spectrum is easily computed with good accuracy.
AB - Ultracompact stars - if they exist - have a unique signature: a discrete spectrum of slowly damped gravitational-wave quasinormal modes. It is known that this feature is due to a potential well present for stars with R < 3M. In this letter we show that the appearance of this well is essentially due to the non-Newtonian behaviour of the centrifugal potential: here we explain this behaviour adopting the optical geometry point of view. This insight leads us to an approximation, valid for highly compact stars, by which the real part of the spectrum is easily computed with good accuracy.
UR - http://www.scopus.com/inward/record.url?scp=0031483932&partnerID=8YFLogxK
U2 - 10.1088/0264-9381/14/12/002
DO - 10.1088/0264-9381/14/12/002
M3 - Article
AN - SCOPUS:0031483932
SN - 0264-9381
VL - 14
SP - L189-L194
JO - Classical and Quantum Gravity
JF - Classical and Quantum Gravity
IS - 12
ER -