2 research outputs found
Gravitational Wave Detection by Interferometry (Ground and Space)
Significant progress has been made in recent years on the development of
gravitational wave detectors. Sources such as coalescing compact binary
systems, neutron stars in low-mass X-ray binaries, stellar collapses and
pulsars are all possible candidates for detection. The most promising design of
gravitational wave detector uses test masses a long distance apart and freely
suspended as pendulums on Earth or in drag-free craft in space. The main theme
of this review is a discussion of the mechanical and optical principles used in
the various long baseline systems in operation around the world - LIGO (USA),
Virgo (Italy/France), TAMA300 and LCGT (Japan), and GEO600 (Germany/U.K.) - and
in LISA, a proposed space-borne interferometer. A review of recent science runs
from the current generation of ground-based detectors will be discussed, in
addition to highlighting the astrophysical results gained thus far. Looking to
the future, the major upgrades to LIGO (Advanced LIGO), Virgo (Advanced Virgo),
LCGT and GEO600 (GEO-HF) will be completed over the coming years, which will
create a network of detectors with significantly improved sensitivity required
to detect gravitational waves. Beyond this, the concept and design of possible
future "third generation" gravitational wave detectors, such as the Einstein
Telescope (ET), will be discussed.Comment: Published in Living Reviews in Relativit
The Role of Binary Pulsars in Testing Gravity Theories
Radio pulsars are neutron stars (NSs) which emit collimated beams of radio waves, observed as pulses, once per rotation of the NS. A subgroup of the radio pulsars behave as highly stable clocks and monitoring the times of arrival of their radio pulses can provide an accurate determination of their positional, rotational, and orbital parameters, as well as indications on the properties of their space-time environment. In this chapter, we focus on the so-called relativistic binary pulsars, recycled NSs orbiting around a compact companion star. Some of them can be used as unique tools to test general relativity and other gravitational theories. The methodology for exploiting these sources as laboratories for gravity theories is first explained and then some of the most relevant recent results are reviewed. <P /