Cosmology from weak lensing

What is cosmic lensing?
Gravitational lensing occurs when a massive celestial body — such as a galaxy cluster — causes a sufficient curvature of spacetime for the path of light around it to be visibly bent, as if by a lens.
The body causing the light to curve is accordingly called a gravitational lens..
What is cosmic shear and weak lensing?
Weak lensing refers to the statistically correlated image distortions of background galaxies due to the foreground matter distribution, also known as “cosmic shear”..
What is galaxy galaxy weak lensing?
Galaxy-galaxy lensing is a specific type of weak (and occasionally strong) gravitational lensing, in which the foreground object responsible for distorting the shapes of background galaxies is itself an individual field galaxy (as opposed to a galaxy cluster or the large-scale structure of the cosmos)..
What is the difference between strong and weak lensing?
As I understand it, strong lensing (just as the name implies) occurs when a source and a gravitational lens are relatively close by and the lens is strong, producing extreme distortions of the light from the source in phenomena such as Einstein rings, weak lensing produces a still distorted image of the source but not .
What is the theory of lensing?
Gravitational lensing occurs when a massive celestial body — such as a galaxy cluster — causes a sufficient curvature of spacetime for the path of light around it to be visibly bent, as if by a lens.
The body causing the light to curve is accordingly called a gravitational lens..
As I understand it, strong lensing (just as the name implies) occurs when a source and a gravitational lens are relatively close by and the lens is strong, producing extreme distortions of the light from the source in phenomena such as Einstein rings, weak lensing produces a still distorted image of the source but not
Galaxy-galaxy lensing is a specific type of weak (and occasionally strong) gravitational lensing, in which the foreground object responsible for distorting the shapes of background galaxies is itself an individual field galaxy (as opposed to a galaxy cluster or the large-scale structure of the cosmos).
Gravitational lensing occurs when a massive celestial body — such as a galaxy cluster — causes a sufficient curvature of spacetime for the path of light around it to be visibly bent, as if by a lens.
The body causing the light to curve is accordingly called a gravitational lens.

Weak gravitational lensing, the tiny distortions in background galaxy shapes, sizes, and fluxes due to the deflection by mass in more nearby objects, is a powerful probe of dark matter and dark energy.

Are weak lensing-induced distortions a powerful probe of dark energy?

Furthermore, the measurement of the weak lensing–induced distortions of the shapes of distant galaxies is a potentially powerful probe of dark energy.
In this review we discuss how this challenging measurement is made and interpreted.
We describe the various systematic effects that can hamper progress and how they may be overcome.

How does a strong gravitational lens affect a line of sight?

While the presence of any mass bends the path of light passing near it, this effect rarely produces the giant arcs and multiple images associated with strong gravitational lensing.
Most lines of sight in the universe are thoroughly in the weak lensing regime, in which the deflection is impossible to detect in a single background source.

What is cluster weak lensing?

More generally, the effect causes small, but statistically coherent, distortions of background sources on the order of 10% (cluster weak lensing).
Abell 1689, CL0024+17, and the Bullet Cluster are among the most prominent examples of lensing clusters.

What is weak gravitational lensing?

Weak gravitational lensing is thus an intrinsically statistical measurement, but it provides a way to measure the masses of astronomical objects without requiring assumptions about their composition or dynamical state.
Distortions of the type produced by lensing, acting on circles and a distribution of ellipses similar to that of real galaxies.

Strong gravitational lensing is a gravitational lensing effect that is strong enough to produce multiple images, arcs, or even Einstein rings.
Generally, for strong lensing to occur, the projected lens mass density must be greater than the critical density, that is mwe-math-element>.
For point-like background sources, there will be multiple images; for extended background emissions, there can be arcs or rings.
Topologically, multiple image production is governed by the odd number theorem.

Cosmology from weak lensing

What is cosmic lensing?

What is cosmic shear and weak lensing?

What is galaxy galaxy weak lensing?

What is the difference between strong and weak lensing?

What is the theory of lensing?

Are weak lensing-induced distortions a powerful probe of dark energy?

How does a strong gravitational lens affect a line of sight?

What is cluster weak lensing?

What is weak gravitational lensing?

Strong gravitational lensing is a gravitational lensing effect that is strong enough