TY - JOUR
T1 - Gravitational Wave Emission from Collisions of Compact Scalar Solitons
AU - Helfer, Thomas
AU - Lim, Eugene A.
AU - Garcia, Marcos A. G.
AU - Amin, Mustafa A.
PY - 2019/2/26
Y1 - 2019/2/26
N2 - We numerically investigate the gravitational waves generated by the head-on collision of equal-mass,
self-gravitating, real scalar field solitons (oscillatons) as a function of their compactness C. We start with
solitons that are initially at rest with respect to each other and show that there exist three different possible
outcomes resulting from their collisions: (1) an excited stable oscillaton for low C, (2) a merger and
formation of a black hole for intermediate C, and (3) a premerger collapse of both oscillatons into individual
black holes for large C. For (1), the excited, aspherical oscillaton continues to emit gravitational waves. For
(2), the total energy in gravitational waves emitted increases with compactness and possesses a maximum
which is greater than that from the merger of a pair of equivalent mass black holes. The initial amplitudes of
the quasinormal modes in the postmerger ringdown in this case are larger than that of collisions of
corresponding mass black holes—potentially a key observable to distinguish black-hole mergers from their
scalar mimics. For (3), the gravitational wave output is indistinguishable from a similar mass, black hole–
black hole merger. Based on our results, LIGO may be sensitive to oscillaton collisions from light scalars of
mass 10−12 eV ≲ m ≲ 10−10 eV.
AB - We numerically investigate the gravitational waves generated by the head-on collision of equal-mass,
self-gravitating, real scalar field solitons (oscillatons) as a function of their compactness C. We start with
solitons that are initially at rest with respect to each other and show that there exist three different possible
outcomes resulting from their collisions: (1) an excited stable oscillaton for low C, (2) a merger and
formation of a black hole for intermediate C, and (3) a premerger collapse of both oscillatons into individual
black holes for large C. For (1), the excited, aspherical oscillaton continues to emit gravitational waves. For
(2), the total energy in gravitational waves emitted increases with compactness and possesses a maximum
which is greater than that from the merger of a pair of equivalent mass black holes. The initial amplitudes of
the quasinormal modes in the postmerger ringdown in this case are larger than that of collisions of
corresponding mass black holes—potentially a key observable to distinguish black-hole mergers from their
scalar mimics. For (3), the gravitational wave output is indistinguishable from a similar mass, black hole–
black hole merger. Based on our results, LIGO may be sensitive to oscillaton collisions from light scalars of
mass 10−12 eV ≲ m ≲ 10−10 eV.
UR - http://www.scopus.com/inward/record.url?scp=85062320669&partnerID=8YFLogxK
U2 - 10.1103/PhysRevD.99.044046
DO - 10.1103/PhysRevD.99.044046
M3 - Article
SN - 1550-7998
VL - 99
SP - 1
EP - 8
JO - Physical Review D (Particles, Fields, Gravitation and Cosmology)
JF - Physical Review D (Particles, Fields, Gravitation and Cosmology)
IS - 4
M1 - 044046
ER -