38 research outputs found
Instabilities of microstate geometries with antibranes
One can obtain very large classes of horizonless microstate geometries
corresponding to near-extremal black holes by placing probe supertubes whose
action has metastable minima inside certain supersymmetric bubbling solutions.
We show that these minima can lower their energy when the bubbles move in
certain directions in the moduli space, which implies that these near-extremal
microstates are in fact unstable once one considers the dynamics of all their
degrees of freedom. The decay of these solutions corresponds to Hawking
radiation, and we compare the emission rate and frequency to those of the
corresponding black hole. Our analysis supports the expectation that generic
non-extremal black holes microstate geometries should be unstable. It also
establishes the existence of a new type of instabilities for antibranes in
highly-warped regions with charge dissolved in fluxes.Comment: 24 pages, 4 figure
Five-dimensional null & time-like supersymmetric geometries
We show that there exist supersymmetric solutions of five-dimensional, pure,
Supergravity such that the norm of the supersymmetric Killing
vector, built out of the Killing spinor, is a real not-everywhere analytic
function such that all its derivatives vanish at a point where the Killing
vector field becomes null. The norm of the Killing vector field then is not an
analytic function on a neighborhood around this point. We explicitly construct
such solutions by using a multi-center Gibbons-Hawking base. Although many of
these solutions have infinite charges, we find explicit examples with finite
charges that asymptote to and discuss their physical
interpretation.Comment: 19 pages, 4 figures, open-vanishing conclusion changed due to
non-analiticity of the Killing vecto
Metastability in Bubbling AdS Space
We study the dynamics of probe M5 branes with dissolved M2 charge in bubbling
geometries with SO(4) x SO(4) symmetry. These solutions were constructed by
Bena-Warner and Lin-Lunin-Maldacena and correspond to the vacua of the
maximally supersymmetric mass-deformed M2 brane theory. We find that
supersymmetric probe M2 branes polarize into M5 brane shells whose backreaction
creates an additional bubble in the geometry. We explicitly check that the
supersymmetric polarization potential agrees with the one found within the
Polchinski-Strassler approximation. The main result of this paper is that probe
M2 branes whose orientation is opposite to the background flux can polarize
into metastable M5 brane shells. These decay to a supersymmetric configuration
via brane-flux annihilation. Our findings suggest the existence of metastable
states in the mass-deformed M2 brane theory.Comment: 38 pages, 8 figure
THE EXPRESSION OF LINE1-MET CHIMERIC TRANSCRIPT IDENTIFIES A SUBGROUP OF AGGRESSIVE BREAST CANCERS
Trous noirs et solutions régulières en théorie des cordes
There exist many smooth solutions in String Theory characterized by a nontrivial topology threaded by fluxes and no localized sources. In this thesis we analyze some of the most important bubbled solutions along with the different purposes they are studied for. Some smooth, eleven-dimensional solutions can be interpreted as BPS black hole microstates in the context of the Fuzzball proposal. One can promote these to be microstates for near-BPS black holes by placing probe supertubes at a metastable minimum inside these solutions. We show that these minima can lower their energy when the bubbles move in certain directions in the moduli space, which implies that these near-BPS microstates are in fact unstable. The decay of these solutions corresponds to Hawking radiation and we compare the emission rate and frequency to those of the corresponding black hole. By modifying the asymptotic behavior of these microstates one could be able to construct microstates for five-dimensional BPS black holes with no electric charge. To do so one needs to find a new supergravity solution in five-dimensions whose Killing vector switches from timelike to null in some open regions. We construct explicit examples where the norm of the supersymmetric Killing vector is a real not-everywhere analytic function such that all its derivatives vanish at a point where the Killing vector becomes null. In the Lin-Lunin-Maldacena solution we find a supersymmetry-breaking mechanism similar to that used for near-BPS microstates. We analyze the potential energy of M2 probes polarized into M5 brane shells. When the charges of the probe are parallel to those of the solution we find stable configurations, while when the charges are opposite we find metastable states that break supersymmetry and analyze the decay process to supersymmetric configurations. We analyze also the Klebanov-Strassler solution and construct its T-dual version in Type IIA. This is done by just reconstructing the solution expanded on a small region of the deformed conifold, after a thorough analysis to choose the most suitable isometry. Our construction is the first step in a program to test the stability of antibranes in Type IIA backgrounds.Il existe des nombreuses solutions lisses dans le domaine de la théorie des cordes, caractérisées par une topologie non triviale (bulles) et sans sources localisées. Dans cette thèse nous analysons quelques-unes parmi les solutions les plus importantes avec les différents objectifs pour lesquels ils sont étudiés. Des solutions lisses en onze dimensions peuvent être interprétées comme microétats BPS de trou noir dans le cadre de la Fuzzball proposal. On peut promouvoir ces microétats à être quasi-BPS en plaçant de supertubes au minimum métastable à l’intérieur de ces solutions. Nous montrons que ces minima peuvent abaisser leur énergie lorsque les bulles se déplacent dans certaines directions dans l’espace des modules, ce qui implique que ces microétats quasi-BPS sont en fait instables. L’énergie dissipée par ces solutions correspond au rayonnement Hawking et on compare le taux d’émission et la fréquence à celles du trou noir correspondant. En modifiant la géométrie asymptotique de ces microétats on pourrait construire des microétats pour des trous noirs BPS sans charge électrique en cinq dimensions. Il faut donc trouver une nouvelle solution de supergravité en cinq dimensions dont la norme du vecteur de Killing passe de positive à nulle dans certaines régions. Nous construisons des exemples explicites où la norme du vecteur de Killing supersymétrique est une fonction réelle non-analytique telle que tous ses dérivés sont nulles à un point où le vecteur de Killing devient nul. Dans la solution de Lin-Lunin-Maldacena on trouve un mécanisme pour briser la supersymétrie similaire à celui utilisé pour les microétats quasi-BPS. Nous analysons l’énergie potentielle de branes M2 polarisés en branes M5. Lorsque les charges des M2 sont parallèles à ceux de la solution, nous trouvons des configurations stables. Lorsque les charges des M2 ne sont pas parallèles, nous trouvons des états métastables qui brisent la supersymétrie et nous analysons le processus de rayonnement d’énergie. Nous analysons aussi la solution de Klebanov-Strassler et construisons sa version T- duale dans la supergravité de type IIA. Pour cela une analyse approfondie est nécessaire pour choisir l’isomérie la plus appropriée. Notre construction est la première étape d’un programme pour tester la stabilité des antibranes dans la supergravité de type IIA