Solitonic Excitations in AdS2

We construct large families of supergravity solutions that are asymptotic to AdS$_2$ and terminate with a cap that is singular in two dimensions but smooth in higher dimensions. These solutions break supersymmetry and conformal invariance. They correspond to finite-energy excitations in empty AdS$_2$ that back-react on the geometry by inducing non-trivial bubbling topology. They are constructed from the novel technique associated with the Ernst formalism for AdS$_D\times\mathcal{C}$ solitons in supergravity [arXiv:2210.06483]. The technique is applied to $D=2$ in M-theory with $\mathcal{C} = S^3\times$T$^6$. The directions of $\mathcal{C}$ degenerate smoothly as a chain of bolts which ends the spacetime in the IR and generates non-supersymmetric bubbles supported by M2-brane flux. Some specific solutions have "flat" directions where the sizes of their bubbles are totally unconstrained and can be arbitrarily tuned while the asymptotics remains fixed. The solitons should correspond to regular non-supersymmetric states of a holographically dual CFT$_1$.Comment: 46 pages, 15 figures, 3 appendices. arXiv admin note: text overlap with arXiv:2210.0648

Topological Stars, Black holes and Generalized Charged Weyl Solutions

We construct smooth static bubble solutions, denoted as topological stars, in five-dimensional Einstein-Maxwell theories which are asymptotic to $\mathbb{R}^{1,3}\times$S$^1$. The bubbles are supported by allowing electromagnetic fluxes to wrap smooth topological cycles. The solutions live in the same regime as non-extremal static charged black strings, that reduce to black holes in four dimensions. We generalize to multi-body configurations on a line by constructing closed-form generalized charged Weyl solutions in the same theory. Generic solutions consist of topological stars and black strings stacked on a line, that are wrapped by electromagnetic fluxes. We embed the solutions in type IIB String Theory on S$^1\times$T$^4$. In this framework, the charged Weyl solutions provide a novel class in String Theory of multiple charged objects in the non-supersymmetric and non-extremal black hole regime.Comment: 39 pages + Appendices, minor changes and typos correcte

The Uplifton

Almost all proposals to construct de Sitter vacua with a small cosmological constant involve flux compactifications with stabilized moduli. These give AdS vacua, which are uplifted to de Sitter by adding antibranes in certain regions of the compactification manifold. However, antibranes are charged, singular and interact nontrivially with other ingredients of the compactification; this can invalidate the de Sitter construction. In this Letter, we construct a new ingredient for uplifting AdS solutions to de Sitter, which is neutral, smooth and horizonless, and therefore bypasses some of the problems of antibrane uplift.Comment: 5 pages, 1 figur

Imaging Topological Solitons: the Microstructure Behind the Shadow

We study photon geodesics in topological solitons that have the same asymptotic properties as Schwarzschild black holes. These are coherent states in string theory corresponding to pure deformations of spacetime through the dynamics of compact extra dimensions. We compare these solutions with Schwarzschild black holes by computing null geodesics, deriving Lyapunov exponents, and imaging their geometries as seen by a distant observer. We show that topological solitons are remarkably similar to black holes in apparent size and scattering properties, while being smooth and horizonless. Incoming photons experience very high redshift, inducing phenomenological horizon-like behaviors from the point of view of photon scattering. Thus, they provide a compelling case for real-world gravitational solitons and topological alternatives to black holes from string theory.Comment: 15 pages and 6 figures, v2: typos corrected, v3: minor changes and published versio

Cavity effect in the quasinormal mode spectrum of topological stars

We study scalar perturbations of topological solitons, smooth horizonless solutions in five-dimensional Einstein-Maxwell theory that correspond to coherent states of gravity via the dynamics of extra compact dimensions. First, we compute scalar quasinormal modes for topological stars that have a single unstable photon sphere, and we show that the spectrum is very similar to that of a black hole with the same photon sphere. Next, we study topological stars that have both a stable inner photon sphere and an unstable one. The first few quasinormal modes are localized around the inner photon sphere. The spectrum also contains ''black-hole like modes'' localized at the unstable outer photon sphere. The frequencies of these modes are similar to those of a black hole, but their imaginary part is smaller due to a cavity effect associated with the inner photon sphere. The longer damping produced by this trapping effect may have implications for black hole spectroscopy.Comment: 17 pages + Appendix, 11 figure