Conveners
Formal Theory: Formal Theory
- Jaroslav Trnka
- Anastasia Volovich
Formal Theory: Formal Theory
- Jaroslav Trnka
- Anastasia Volovich
Formal Theory: Formal Theory
- Jaroslav Trnka
- Anastasia Volovich
Formal Theory: Formal Theory
- Jaroslav Trnka
- Anastasia Volovich
Formal Theory: Formal Theory
- Jaroslav Trnka
- Anastasia Volovich
In this work, we propose a Greenโs basis and a new physical basis for dimension-seven (dim-7) operators, which are suitable for the matching of ultraviolet models onto the Standard Model effective field theory (SMEFT) and the deviation of renormalization group equations (RGEs) for the SMEFT dim-7 operators. The reduction relations to convert operators in the Greenโs basis to those in the...
We present a general family of effective $SU(2)$ models with an adjoint scalar. We construct the Bogomol'nyi-Prasad-Sommerfield (BPS) limit and derive monopole solutions in analytic form. In contrast to the 't Hooft-Polyakov monopole, included here as a special case, these solutions tend to exhibit more complex energy density profiles. Typically, we obtain monopoles with a hollow cavity at...
The theory of an independent Higgs field is given by an $\textrm{O}(N)$ model with an $N$-component scalar $\vec{\phi}$ and a quartic $\lambda(\vec{\phi}\cdot\vec{\phi})^2$ potential when $N=4$. The phase structure of the theory can be studied analytically for all values of the coupling $\lambda$ using the large-$N$ limit, both at zero and finite temperature. However, authors in the 70s and...
The electroweak hierarchy problem and the naturalness framework have been a
driving theme for model building beyond the Standard Model of particle physics.
In the case of the Higgs boson, the problem lies in the difficulty of
producing a model where the Higgs mass is insensitive to parameters in the
ultraviolet (UV) completed theory. With time, more traditional solutions to
the hierarchy...
The ultimate dream of unification models consists in combining both gauge and Yukawa couplings into one unified coupling. This is achieved by using a supersymmetric exceptional E6 gauge symmetry together with asymptotic unification in compact five-dimensional space-time. The ultraviolet fixed point requires exactly three fermion generations: one in the bulk, and the two light ones localised on...
The multi-gluon exchanges between quark loops constitute a contribution to confining force inside hadronic states at vanishing transferred momenta and finite strong coupling. In this talk, we present calculations of QCD corrections to Coulomb potential in the configuration of multi-gluon exchanges between two quark loops (four-quark scattering amplitude) in the limit of vanishing transferred...
From black hole quasinormal frequencies (QNFs), we can extract characterising information about their perturbed source. In the case of charged black holes, we can interrogate the extendability of the metric past the Cauchy horizon as well as the role of superradiance in black hole evolution. Here, we examine the QNF spectrum corresponding to a massive scalar test field carrying an electric...
I will describe recent results on the double copy for amplitudes in (A)dS4 and their soft limits, which are relevant for holography and cosmology.
The duality between color and kinematics and associated double-copy construction has proven remarkably useful as a computational tool first in integrand construction at the multi-loop level, and more recently in efficiently constructing the contributions of higher derivative operators. Intriguingly double-copy consistency relates information measured in the IR to behavior in the UV. I will...
We show how to construct the moduli-space integrands for one-loop superstring amplitudes from the knowledge of 10D field-theory loop integrands in the BCJ form. Our map provides an alternative to intricate computations involving worldsheet supersymmetry. This construction is a one-loop higher-point analogue of a recent conjecture for the three-loop four-point superstring amplitude.
Abstract: The effective field theory (EFT) approach for new physics has risen to a prominent role given the current status of the LHC. However, the large number of operators in the Standard Model EFT (SMEFT) calls for a new organizing principle. In this talk, I will introduce the geometry construction for EFT that manifests the invariance from field redefinition and neatly organizes physical...
Black holes, neutron stars and other compact gravitating objects can be described at long distances by a point particle effective field theory. In such effective theory, tidal effects and/or the dynamics of the horizon are captured in a series of Wilson coefficients, the so-called Love numbers, which can be determined by matching with a complete description of the compact object in general...
Recently, Arkani-Hamed et al. proposed the existence of zeros in scattering amplitudes in certain quantum field theories including the cubic adjoint scalar theory Tr($\phi^3$), the $SU(N)$ non-linear sigma model (NLSM) and Yang-Mills (YM) theory. These hidden zeros are special kinematic points where the amplitude vanishes and factorizes into a product of lower-point amplitudes, similar to...
We study the (ambi-)twistor model for spinning particles interacting via electromagnetic field, as a toy model for studying classical dynamics of gravitating bodies including effects of both spins to all orders. The all-orders-in-spin effects are encoded as a dynamical implementation of the Newman-Janis shift, and we find that the expansion in both spins can be resummed to simple expressions...
We will report on recent progress on obtaining classical observables in general relativity from the heavy-mass effective theory. As a concrete example we will discuss the NNLO corrections to the radiation produced by the scattering of two heavy scalars modelling Schwarzschild blackholes. I will also describe how to extract waveforms from this result using the observable based KMOC approach.
We will discuss the computation of classical tree-level five-point scattering amplitudes for the two-to-two scattering of spinning celestial objects with the emission of a graviton. Using this result, we will then turn to the computation of the leading-order time-domain gravitational waveform. The method we describe is suitable for arbitrary values of classical spin of Kerr black holes and...
Gravity is a fundamental theory of physics, but due to its weakness, our understanding of it remains limited. Despite our knowledge of it being restricted due to its weakness, recent computational advancements, initially developed for the Standard Model, have provided us with new tools to explore its effects. It has opened up exciting opportunities to study gravitational interactions and...
The double copy is a powerful tool allowing us to obtain amplitudes in gravity from simpler ones in gauge theory. It was originally derived from string theory, relating the tree level amplitudes of closed string amplitudes to two copies of open string amplitudes. In the field theory limit, this reduces to being able to obtain tree-level graviton amplitudes from the "square" of tree-level gluon...
I will review determinant operators in N=4 super Yang-Mills theory with gauge group SU(N), which are half BPS dimension N operators, also known as giant gravitons. I will discuss our recent paper on the 4-point correlation function of two dimension 2 superconformal primary operators and two determinant operators, which is dual, by AdS/CFT, to two gravitons scattering off a D3-brane that moves...
In this talk we will discuss how two objects of great interest to both physicists and mathematicians are connected.
On one hand, amplituhedra are the image under a linear map of the positive part of the Grassmannian -- where all the Pluckers are nonnegative. Introduced by physicists to encode scattering amplitudes in N=4 super Yang-Mills theory, they are semialgebraic sets which generalize...
We study a novel geometric expansion for scattering amplitudes in planar $\mathcal{N}=4$ super Yang-Mills theory in the context of the Amplituhedron which reproduces the all-loop integrand as a canonical differential form on the positive geometry. By considering the integrand in terms of negative rather than positive geometries, it has previously been shown that one gets a sum of terms that...
The Correlahedron describes correlation functions in maximally supersymmetric Yang-Mills theory. In this talk, I present an alternative geometric formulation. This allows us to study the loop geometry using a novel idea of so-called chambers. We characterize the boundary structure of the chambers and compute their canonical form up to three loops.
I will review the application of techniques from Grรถbner theory and tropical geometry to describe the singularities of massless scattering amplitudes.
I will describe recent progress on phrasing the kinematic algebra at the heart of the color-kinematic duality in terms of a quasi-shuffle Hopf algebra. First, in the heavy-mass effective field theory (HEFT) limit, the algebra is shown to easily generalize from Yang-Mills to DF^2+YM theory. This theory contains \alphaโ corrections to Yang-Mills and is relevant for bosonic string amplitudes....
In recent years modern amplitude methods have been successfully applied to so-called exceptional scalar effective field theories, chief among them the non-linear sigma model (NLSM) describing the dynamics of pions. A hallmark feature of NLSM amplitudes is their vanishing soft behavior (Adler zero) which was crucial for the formulation of on-shell recursion relations at tree-level.
In this...
I present recent efforts to tame the algebraic complexity of two-loop five-point scattering amplitudes in the spinor helicity formalism. These amplitudes are required, for instance, to obtain next-to-next-to-leading order predictions for the production of three jets or of a massive vector boson with two jets at the Large Hadron Collider. I review the method of numerical generalized and the...
Recent developments on Feynman integrals and string amplitudes greatly benefitted from multiple polylogarithms and their elliptic analogues โ iterated integrals on the sphere and the torus, respectively. In this talk, I will review the Brown-Levin construction of elliptic polylogarithms and propose a generalization to Riemann surfaces of arbitrary genus. In particular, iterated integrals on a...
We consider the 5-mass kite family of self-energy Feynman integrals and present a systematic approach for putting its associated differential equation into a convenient form (also called the epsilon or canonical form).
We show that this is most easily achieved by making a change of variables from the kinematic space to the function space of two tori with punctures.
We demonstrate how the...
In the context of high-energy particle physics, a reliable theory-experiment confrontation requires precise theoretical predictions. This translates into accessing higher-perturbative orders, and when we pursue this objective, we inevitably face the presence of complicated multiloop Feynman integrals. There are serious bottlenecks to compute them with classical tools: the time to explore novel...
