What is the meaning of "BPS D-branes"?

[chongchong]

I often read the statement like the following;

"A state of D-branes parallely pleced in flat 10 dim space is a BPS state, because some of superchages remain unbroken."


I think that every "BPS state" is one member(state) of a certain BPS multiplet.
So my question is:

Which state of the BPS multiplet dose a state of parallely pleced D-branes correspond to?

[blechman]

I often read the statement like the following;

"A state of D-branes parallely pleced in flat 10 dim space is a BPS state, because some of superchages remain unbroken."


I think that every "BPS state" is one member(state) of a certain BPS multiplet.
So my question is:

Which state of the BPS multiplet dose a state of parallely pleced D-branes correspond to?

A "BPS State" is a solution to the field equations that preserves some (but not all) of the supersymmetries of the field equations. Branes are BPS solutions of the supergravity equations under this definition, and that is why you see statements like the one you quoted.

The "BPS Multiplet" you are referring to would correspond to what you get if you act on the stack of branes with one of the unbroken supersymmetry transformations. This would probably give you things like translations and rotations of the stack, etc.

[chongchong]

Thank!

I often read the statement like the following;

"A state of D-branes parallely pleced in flat 10 dim space is a BPS state, because some of superchages remain unbroken."


I think that every "BPS state" is one member(state) of a certain BPS multiplet.
So my question is:

Which state of the BPS multiplet dose a state of parallely pleced D-branes correspond to?

[smith345]

The "BPS Multiplet" you are referring to would correspond to what you get if you act on the stack of branes with one of the unbroken supersymmetry transformations. This would probably give you things like translations and rotations of the stack, etc.