Physics Letters B 763 (2016) 427–433
Contents lists available at ScienceDirect
Physics Letters B
www.elsevier.com/locate/physletb
LIGO GW150914 and GW151226 gravitational wave detection
and generalized gravitation theory (MOG)
J.W. Moffat
a,b,∗
a
Perimeter Institute for Theoretical Physics, Waterloo, ON N2L 2Y5, Canada
b
Department of Physics and Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, Canada
a r t i c l e i n f o a b s t r a c t
Article history:
Received
27 May 2016
Received
in revised form 16 August 2016
Accepted
3 October 2016
Available
online 4 November 2016
Editor:
M. Trodden
The nature of gravitational waves in a generalized gravitation theory is investigated. The linearized
field equations and the metric tensor quadrupole moment power and the decrease in radius of an
inspiralling binary system of two compact objects are derived. The generalized Kerr metric describing
a spinning black hole is determined by its mass M and the spin parameter a = cS/GM
2
. The LIGO-
Virgo
collaboration data is fitted with smaller binary black hole masses in agreement with the current
electromagnetic, observed X -ray binary upper bound for a black hole mass, M 10M
.
© 2016 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP
3
.
1. Introduction
A century after the fundamental prediction by Einstein, based
on his gravitational field equations [1] of gravitational waves [2,3],
and Schwarzschild’s derivation of his solution to the general rel-
ativity
(GR) field equations [4], which led to the prediction of
black holes, the first direct detections of gravitational waves has
been reported [5,6]. The gravitational waves are produced by the
merging of a binary black hole system to form a single black
hole. The measurements lead to a new access to the physi-
cal
properties of spacetime and strong field gravity. The obser-
vations
of the energy loss by Taylor and Weisberg [7], follow-
ing
the discovery of the binary pulsar system PSR B1913+16 by
Taylor and Hulse [8] demonstrated the existence of gravitational
waves.
In
the following, we will investigate the nature of gravitational
waves in a generalized gravitation theory calle d Scalar–Tensor–
Vector–Gravity
(STVG), also known in the literature as MOG (mod-
ified
gravity) [9]. The theory has been studied as an alternative
to GR without (detectable) dark matter in the present universe,
and fits to galaxy rotation curves and galaxy clusters have been
obtained [10–12]. Moreover, the theory has been applied to cos-
mology
with an explanation for the growth of structure in the
early universe and fits have been obtained to the CMB data [14,
15].
In the early universe cosmology, the mass of the vector field
*
Correspondence to: Perimeter Institute for Theoretical Physics, Waterloo, ON
N2L 2Y5, Canada.
E-mail
address: jmoffat@perimeterinstitute.ca.
φ
μ
is m
φ
10
−22
eV and acts as a cold dark matter particle
with density ρ
φ
> ρ
b
, where ρ
φ
and ρ
b
denote the density of
the boson particle and baryons, respectively. As the universe ex-
pands
and enters the era of the formation of stars and galaxies
the effective boson mass decreases to the value m
φ
∼ 10
−28
eV,
and due to the weak gravitational coupling of the particle to or-
dinary
matter the particle will be unobservable in the late-time
universe.
An
alternative early universe cosmology without dark matter is
formulated in [16].
In
our generalized gravitational theory electromagnetic waves
(photons) and gravitational waves (gravitons) move with the speed
of light. The null geodesic equation for photon paths is determined
in a Jordan frame conformal metric, and in the Einstein frame met-
ric
the gravitational constant for photon paths is screened, yielding
the deflection of light by the Sun, and the Shapiro time delay in
agreement with GR. The enhanced gravitational interaction expe-
rienced
by photons in the lensing of galaxies and galactic clusters
leads to an explanation of gravitational lensing data without dark
matter [13].
The
paper is organized, as follows. In Section 2, we present the
STVG field equations, while in Section 3, we investigate the lin-
earized
weak field approximation of the field equations, the mod-
ified
two-body acceleration law and the tensor gravitational wave
equations for a binary system. Section 4, presents the generalized
Kerr solution of the gravielectric vacuum STVG field equations,
while in Section 5, we investigate the inspiralling merger of two
black holes and the LIGOGW150914 and GW151226 detections of
gravitational waves. In Section 5, we discuss the measurements of
black hole masses, and we end with conclusions in Section 6.
http://dx.doi.org/10.1016/j.physletb.2016.10.082
0370-2693/
© 2016 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by
SCOAP
3
.