Ponente
Dr.
torrente-lujan emilio
(universidad de murcia)
Descripción
We present a detailed description of $N=2$ stationary
BPS multicenter black hole solutions for quadratic prepotentials
with an arbitrary number of centers and scalar fields
making a systematic use of the algebraic properties of the matrix of second derivatives of the prepotential, $\mathcal{S}$, which in this case is a scalar-independent matrix. In particular we obtain bounds on the physical parameters of the multicenter solution such as horizon areas and ADM mass. We discuss the possibility and convenience of setting up a basis of the symplectic vector space built from charge
eigenvectors of the $\ssigma$, the set of vectors
$(\Ppm q_a)$ with $\Ppm$ $\ssigma$-eigenspace projectors.
The anti-involution matrix $\mathcal{S}$ can be understood
as a Freudenthal duality $\tilde{x}=\ssigma x$.
We show that this duality can be generalized to
``Freudenthal transformations''
$$x\to \lambda\exp(\theta \ssigma) x= a x+b\tilde{x}$$
under which the horizon area, ADM mass and intercenter
distances scale up leaving constant the scalars at the fixed points.
In the special case $\lambda=1$, ``$\ssigma$-rotations'',
the transformations leave invariant the solution.
The standard Freudenthal duality can be written as
$\tilde x= \exp\left(\frac{\pi}{2} \ssigma\right) x .$
We argue that these generalized transformations leave
invariant not only the quadratic prepotential theories
but also the general stringy extremal quartic form $\Delta_4$,
$\Delta_4(x)= \Delta_4(\cos\theta x+\sin\theta\tilde{x})$
and therefore its entropy at lowest order.
Autor primario
Dr.
torrente-lujan emilio
(universidad de murcia)
Coautor
Dr.
jose juan fernandez-melgarejo
(harvard university)
