# What are B mode and E mode signals?

• man@SUT
In summary, the conversation discusses technical terms such as "B mode signal", "E mode signal", and "k" in relation to an article about dark matter maps and gravitational lensing. The E mode is a measure of the stretching of light due to gravitational effects, while the B mode is considered a noise component. The article recommends further reading on gravitational lensing basics and E-B mode decomposition for clarification.
man@SUT
I've read an article in nature and found technical words "B mode signal" and "E mode signal". I don't understand what they are. In a website, they say it's like the electromagnetic field line but I'm still not clear.

I also don't understand what k means in " the linear greyscale shows the E-mode lensing convergence field k(Kappa)". I think it's also the technial word.

The article is about the dark matter maps.

I do not know the details but this is known as E-B mode decomposition. Basically the E-mode is a measure of the stretching (shear) of the light source that is weak lensed. This mode is curl free and is generated by gravitational effects. As far as I know the other mode maps, the B-mode maps, are the noise components that cannot be identified with the gravitational physics of the lens.

http://astro.berkeley.edu/~jcohn/lens.html

And this one about E-B mode decomposition (end of the page):
http://www.lsst.org/Science/Cosmic_Shear.shtml

Last edited by a moderator:
Thank you very much, Mr Hellfire.

I'll try to search again from those links.

## What are B mode and E mode signals?

B mode and E mode signals are two different types of polarizations in electromagnetic radiation. They refer to the direction in which the electric and magnetic fields of the radiation oscillate.

## What is the difference between B mode and E mode signals?

The main difference between B mode and E mode signals is their direction of oscillation. B mode signals have a circular or elliptical direction of oscillation, while E mode signals have a linear direction of oscillation.

## How are B mode and E mode signals used in science?

B mode and E mode signals are used in a variety of scientific fields, including astrophysics, cosmology, and radar technology. They play a crucial role in understanding the properties of the universe and in developing advanced communication and imaging technologies.

## What are some examples of B mode and E mode signals?

Examples of B mode signals include the cosmic microwave background radiation, which has a B mode polarization pattern, and circularly polarized radio waves used in satellite communications. Examples of E mode signals include linearly polarized light used in 3D movies and TV screens, and horizontally polarized radio waves used in AM radio broadcasting.

## How are B mode and E mode signals measured and detected?

Scientists use specialized instruments, such as polarimeters and interferometers, to measure and detect B mode and E mode signals. These instruments are designed to detect the direction of oscillation of the electric and magnetic fields in electromagnetic radiation.

• Cosmology
Replies
11
Views
6K
• Classical Physics
Replies
3
Views
679
• New Member Introductions
Replies
2
Views
54
• Optics
Replies
2
Views
2K
• Electromagnetism
Replies
5
Views
694
• Special and General Relativity
Replies
27
Views
2K
• Electrical Engineering
Replies
1
Views
909
• Astronomy and Astrophysics
Replies
6
Views
3K
• Engineering and Comp Sci Homework Help
Replies
13
Views
1K
• Astronomy and Astrophysics
Replies
3
Views
2K