相关论文: Stellar Gravitational Lens Engineering for Interst…
We discuss strong gravitational lensing by multiple objects along any line of sight. The probability for strong gravitational lensing by more than one lens is small, but a number of strong lens systems in which more than one separate lens…
Strong gravitational lensing at the galaxy scale is a valuable tool for various applications in astrophysics and cosmology. The primary uses of galaxy-scale lensing are to study elliptical galaxies' mass structure and evolution, constrain…
The primary challenge of rocket propulsion is the burden of needing to accelerate the spacecraft's own fuel, resulting in only a logarithmic gain in maximum speed as propellant is added to the spacecraft. Light sails offer an attractive…
When transmitting a signal over a large distance it is more efficient to send a brief beamed signal than a continuous omni-directional transmission but this requires that the receiver knows where and when to look for the transmission. For…
Optical interferometry provides us with a unique opportunity to improve our understanding of stellar structure and evolution. Through direct observation of rotationally distorted photospheres at sub-milliarcsecond scales, we are now able to…
Lightsails are a highly promising spacecraft concept that has attracted interest in recent years due to its potential to travel at near-relativistic speeds. Such speeds, which current conventional crafts cannot reach, offer tantalizing…
Low-mass probes propelled by directed energy from earth are an early option for exploration of nearby star systems. A challenging aspect of such technology is returning scientific observational data to earth. We compare two configurations…
Gravitational lensing has established itself as a valuable tool in many astrophysical fields in the roughly 20 years of its existence as an observational science. In this brief review, first the basics of lensing are introduced. Then it is…
We utilize the well-established properties of the solar gravitational lens (SGL) to consider realistic observational scenarios. Actual exoplanets, which may be the target of an SGL observational campaign, are not stationary. Their…
Gravitational lenses are a unique new constraint on the structure of galaxies. We review the evidence that most lenses are early-type galaxies, the optical properties of the lens galaxies, the evidence against constant M/L models, recent…
Exoplanet imaging using the solar gravitational lens is an enticing prospect. The fundamental physical properties of the lens, including its angular resolution and light amplification, promise exceptional capabilities. These expectations,…
Building upon earlier work, we explore the limits of using a configuration of satellites to measure the trace of the gravitational gradient tensor using intersatellite laser ranging and timing observables without relying on high-precision…
The Solar Gravitational Lens (SGL) is a gift of nature that Humanity is now ready to exploit. SGL physics started with Einstein's 1936 paper on the gravitational lensing; it was not until 1979 that the idea of a space mission reaching the…
The past decades have witnessed a lot of progress in gravitational lensing with two main targets: stars and galaxies (with active galactic nuclei). The success is partially attributed to the continuous luminescence of these sources making…
Relativistic stellar jets, produced in binary systems called microquasars, propagate through media with different spatial scales releasing their energy in the form of work and radiation from radio to gamma rays. There are several…
We investigate the utility of a constellation of four satellites in heliocentric orbit, equipped with accurate means to measure intersatellite ranges, round-trip times and phases of signals coherently retransmitted between members of the…
Strong lensing is a powerful tool to address three major astrophysical issues: understanding the spatial distribution of mass at kpc and sub-kpc scale, where baryons and dark matter interact to shape galaxies as we see them; determining the…
Like light, gravitational waves can be gravitationally lensed by massive astrophysical objects. Strong gravitational lensing by galaxies and galaxy clusters is anticipated to become observable in the coming years. This phenomenon will…
The gravitational field of the sun will focus light from a distant source to a focal point at a minimal distance of 550 Astronomical Units from the sun. A proposed mission to this gravitational focus could use the sun as a very large lens,…
Strong gravitational lenses allow us to peer into the farthest reaches of space by bending the light from a background object around a massive object in the foreground. Unfortunately, these lenses are extremely rare, and manually finding…