The AdS/CFT duality provides a correspondence between correlation functions at weak coupling on the gravity side and at strong coupling for its field theory counterpart. However correlation functions are notably hard to compute in this regime, and I report on how modern analytical bootstrap methods can be used in order to derive defect two-point functions up to next-to-leading order, by using...
3d N=4 theories are of particular interest as they admit various types of twists (topological-holomorphic). A framework with interesting implications is the one of topologically twisted 3d N=4 theories with holomorphic boundaries/defects. The significance of these configurations relies on the fact that local boundary operators form special Vertex operator algebras, the study of which can...
I will discuss confinement in 4d $\mathcal{N=1}$ $SU(N)$ Super-Yang Mills from a holographic point of view, focusing on the 1-form symmetry and its relation to chiral symmetry breaking. We will see how to identify the topological couplings that determine the 1-form symmetry and its ’t Hooft anomalies from the 5d supergravity dual, obtained by truncation of the Klebanov-Strassler solution. One...
In this talk, I will review our recent progress on the characterization of multipoint conformal blocks in any spacetime dimension $d$ and any OPE channel.
Our approach extends the standard four-point Casimir equations, introduced by Dolan and Osborn, to a set of higher-point eigenvalue equations of commuting operators that also measure quantum numbers associated with vertices of OPE diagrams....
The conformal bootstrap is a powerful, nonperturbative method to study
conformal field theories (CFTs). Advancements in especially the numerical bootstrap have led to extremely precise results for the computation of critical exponents in various CFTs, and the conformal bootstrap
has gained a lot of attention in recent years. The conformal bootstrap can be
generalized/modified to include...
We use analytical bootstrap techniques to study supersymmetric monodromy de-
fects in the critical Wess-Zumino model. In preparation for our main result we first study two related systems which are interesting on their own: general monodromy defects (no susy), and the ε–expansion bootstrap for the Wess-Zumino model (no defects). For general monodromy defects we discuss some subtleties...
In this brief talk I will show how to compute the CFT data and the four-point function in 1D CFTs from unitarity. First I will review the OPE inversion formula, which allows to recover the spectrum and OPE coefficients from the double discontinuity of a Regge bounded four-point function. Then I will explain how to use it to find the CFT data in a perturbative expansion around Generalized Free...
One dimensional CFTs are an exceptional laboratory in which we can test novel techniques in order to solve higher dimensional CFTs. They are also interesting from an holographic point of view, as in the case of conformal line defects in 4d N=4 Super Yang-Mills. In this short talk, I will present a recursive prescription to compute, up to one loop, 4d N=4 SYM n-point correlation functions...
The Festina Lente (FL) bound arises from demanding that very large charged black holes in universes with a positive cosmological constant must decay without becoming singular. The FL bound states that the mass of all charged states is bounded from below by a scale set by the vacuum energy.
In this talk, I will first review the argument for the FL bound from charged black hole decay. I will...
6D SCFTs admit a plethora of global symmetries that
specify subtle global properties, such as 2-form symmetries.
When coupled to gravity those symmetries are expected to be
either broken or gauged.
In this talk I present a simple geometric condition for the
later option to be the case that is applicable to (2,0) and
(1,0) theories. I give further evidence by relating such examples to...
Type IIB supergravity famously has a discrete duality group,
which is an exact symmetry of the full type IIB string theory. This
symmetry has potential quantum anomalies, which could render the theory
inconsistent. In this talk I will describe how we computed these
anomalies in recent work, and show they are nonvanishing, but
remarkably, they can be cancelled by a subtle modification of...
In this talk we discuss a novel approach to moduli stabilization in Type IIB flux compactifications. Our strategy relies on recent insights about Calabi-Yau moduli spaces based on asymptotic Hodge theory. The crucial observation is that exponential corrections must be present near most boundaries in these moduli spaces. We then use these corrections to engineer new flux vacua with an...
Obtaining string compactifications where the KK scale is much higher than the cosmological constant scale is quite challenging. Such a separation of scales is however necessary for the theory to be genuinely lower-dimensional.
In massive type IIA string theory there are such scale-separated vacua, e.g. the DGKT AdS$_4$ solutions. It has been shown recently that the classical orientifold...
Scattering amplitudes in quantum field theories have intricate analytic properties as functions of the energies and momenta of the scattered particles. In perturbation theory, their singularity structure is governed by nonlinear polynomial systems known as Landau equations. In this work we introduce several tools from computational algebraic geometry to solving Landau equations for any...
This work is about a duality between two seemingly unrelated objects. The hypersimplex $\Delta_{k+1,n}$ -- a polytope of dimension $n-1$ in $\mathbb{R}^n$ -- has been the center of attention of both mathematicians and physicists, in connection with the moment map, torus orbits in the Grassmannian, tropical geometry and cluster algebras. Meanwhile, the amplituhedron $\mathcal{A}_{n,k,2}$ --...
In this talk we will analyse loop corrections to a conformally coupled scalar field with a quartic self-interaction in $(A)dS_4$ from a holographic perspective. First we will remark on the similarities and differences of quantum field theory in $AdS$ and $dS$. We will then calculate the quantum corrections to the four point function and give a formula for the anomalous dimensions of the dual...
11D supergravity has been conjectured to be the low-energy limit of a fundamental theory, also known as M-Theory, which would contain non-perturbative information of string theory. In this talk, I will discuss the so-called 11D pure spinor superparticle whose quantization describes 11D supergravity in its antifield formulation. Since scattering amplitudes require the introduction of vertex...
We revisit the computation of string correlation functions in AdS3 with pure NS-NS flux from a worldsheet point of view. These correlators contain all the perturbative information about the spacetime CFT and the existence of winding strings in AdS3 makes them very rich. We propose a solution to the problem of computing these correlators. The winding correlators encode information about...
In general it is extremely difficult to obtain exact non-perturbative information about the operator product expansion (OPE) of a given CFT. In this quest protected sectors play an incredibly important role as in some cases they allow us to obtain the full answer for a subset of the operators in the theory. Important examples of this phenomenon occur in 4d $\mathcal{N}=2$ and 6d...
In this talk, I will talk about the Post-Newtonian expansion of the gravitational three-body effective potential at the 2nd Post-Minkowskian order. At order 2PM a formal result is given in terms of a differential operator acting on the maximal generalized cut of the one-loop triangle integral. We perform the PN expansion unambiguously at the level of the integrand. Finding agreement with the...
We construct the complete (planar and non-planar) integrand for the
six-loop four-point amplitude in maximal $D\le10$ super-Yang-Mills.
This construction employs new advances to help combat the
proliferation of state-sums and loops in the evaluation of
multi-loop $D$-dimensional unitarity cuts. Concretely, we introduce
two graph-based approaches, applicable in a range of...
In this talk I will show how concepts from Calabi-Yau geometry and especially Calabi-Yau motives can be used for computations of multi-loop Feynman integrals. This will be exemplified with the so called banana graphs. First, I will give a short introduction to Feynman integrals and Calabi-Yau manifolds. Then we will see how the mathematics of Calabi-Yau manifolds (variations of Hodge...
Non-geometric solutions of type IIB supergravity - called S-folds - have recently attracted a lot of attention. They are of particular interest as they can easily be seen as solutions of 4D and 5D gauged maximal supergravity. Moreover, they are conjectured to be the holographic dual of certain localized interfaces in SYM$_4$.
In this talk we will review such solutions and focus on their...
In three spacetime dimensions certain gravitational and gauge theories are `third way' consistent. This means that their equations of motion are only on-shell consistent and do not come from the variation of an action which contains the dynamical field alone. Although this mechanism is not special to 3d, no higher dimensional third way consistent theory was known. In this talk, I will...
Based on reasonable assumptions, we propose a new expression for Lloyd's bound, which confines the complexity growth of charged black holes. We then compute the holographic complexity for charged black branes in the presence of a finite cutoff using complexity = action proposal. We argue that a behind-the-horizon cutoff is inevitable. Using the proposed Lloyd's bound, we find a relation...
We argue that in extended supergravity, de Sitter ctitical points with light charged gravitini violate the magnetic weak gravity conjecture. We prove this statement in general for N=2 matter-coupled gauged supergravity and demonstrate the result and its caveats through various examples. This result is required by the "festina lente" bound, but is derived independently, and thus serves as a...
We provide a string theoretical explanation of fuzzy dark matter as composed by ultra-light axions coming from the compactification of type IIB string theory on Calabi-yau manifolds. In particular, we consider C_4 axions stabilased in a Large Volume Scenario, and thraxions, axionic modes living in warped throats of the internal manifold. Based on the latest bounds, we study how likely is for...
Axion fields coupled to gravity allow non-trivial Euclidean saddle points that correspond to wormholes. Their possible role in the path integral of quantum gravity has been a puzzle for over 30 years. In this talk I will first explain that these saddle points are unstable in a Euclidean sense even when additional axion or saxion fields are added. Secondly, the meaning of these instabilities...
We conjecture that in a consistent supergravity theory with non-vanishing gravitino mass, the limit $m_{3/2}→0$ is at infinite distance. In particular one can write $m_{tower}∼m^δ_{3/2}$ so that as the gravitino mass goes to zero, a tower of KK states as well as emergent strings becomes tensionless. This conjecture may be motivated from the Weak Gravity Conjecture as applied to strings and...
Universal relationships between asymptotic symmetries, QFT soft theorems, and low energy observables have reinvigorated attempts at formulating a holographic correspondence for flat spacetimes. In this talk, I will review recent advances in the celestial holography proposal, where the 4d S-matrix is reconsidered as a 2d correlator on the celestial sphere at null infinity.
I will report on recent progress in bootstrapping the $\alpha'$-expansion of the genus-zero four-point superstring amplitude on AdS_5, dual to correlation functions of N=4 SYM at strong coupling. The construction of these amplitudes goes hand in hand with a deeper understanding of the spectrum of double-trace operators. As I will explain, at the level of supergravity these operators exhibit an...
The discovery of integrability in planar N=4 sYM theory led to considerable advances in the computation of planar anomalous dimensions. In this talk I will discuss universal statistical properties of anomalous-dimension spectra in sYM theories in the planar limit and at finite rank of the gauge group. I will show how they can give insight into the nature of the underlying model, in particular...
I will review the Standard Model Effective Field Theories (SMEFT) from purely on-shell arguments. Starting from few basics assumptions such as Poincaré invariance and locality, it is possible to classify all the renormalizable and non-renormalizable interactions at the lowest order in the couplings. From these building blocks, locality and unitarity enforce Lie algebra structures to appear in...
