Graviton bosonic degrees of freedom

[Neitrino]

Hi,

Could you pls advise me why in on-shell case graviton has two degrees of freedom?
and in general how do I calculate bosonic or fermionic degrees of freedom of any particle?

I was reading some books about supersummetry and stuck when they said gravitopn has two degrees of freedom and gravitiono also...

thanks a lot

 

[samalkhaiat]

See my posts (only MY posts) in the following threads:

www.physicsforums.com/showthread.php?t=192572
www.physicsforums.com/showthread.php?t=91769
www.physicsforums.com/showthread.php?t=252102
www.physicsforums.com/showthread.php?t=237936

regards

sam

 

[Entropia]

The concept of degrees of freedom in particle physics refers to the number of independent variables needed to fully describe the state of a particle. In the case of bosons, the spin of the particle determines its degrees of freedom, with spin 0 particles having one degree of freedom, spin 1 particles having two degrees of freedom, and spin 2 particles having three degrees of freedom.

In the case of gravitons, which are spin 2 particles, there are two possible polarization states - one with spin aligned with the direction of motion and one with spin anti-aligned. This is why gravitons are said to have two degrees of freedom.

Calculating the degrees of freedom for a particle can be done by looking at its quantum numbers, such as spin, charge, and mass. For example, fermions have half-integer spin and therefore have an odd number of degrees of freedom, while bosons have integer spin and have an even number of degrees of freedom.

In the case of supersymmetry, which is a theoretical framework that proposes a symmetry between fermions and bosons, the graviton has a superpartner known as the gravitino. This is why both the graviton and gravitino are said to have two degrees of freedom in supersymmetric theories.

I hope this helps to clarify the concept of degrees of freedom for you. If you have any further questions, please feel free to ask.