arXiv subjects

Stephanie Baines

Publications and source records attributed to Stephanie Baines.

4 recordsLinked to original sources

arXiv2026

EFTs with Symmetric Moduli Spaces: the Landscape and the Swampland

The Swampland Distance Conjecture (SDC) states that, for any infinite-distance limit in the moduli space of a quantum gravity effective field theory (EFT), there should exist an infinite tower of states that become exponentially light. According to the Emergent String Conjecture, such a tower should consist either of tensionless strings or of Kaluza-Klein modes, each with a mass-decay rate that depends in a precise way on the dimension of the effective field theory. In this paper, we use the results obtained in arXiv:2508.18401 on the SDC for symmetric moduli spaces and how these rates are encoded in the weight polytope of the corresponding particle-state representations to determine the symmetric space EFTs and representations that have these decay rates. Remarkably, assuming that the particle states transform in an irreducible representation, the list of possible polytopes and moduli spaces is finite. Different EFTs are related by embedding one moduli space in another or by taking a decompactification limit. Requiring compatibility of the particle representations under such branching, we find that, while most of the theories can be obtained from an EFT based on $E_{8(8)}$, there remain three in our list that appear to be impossible to get from M- or string-theory compactifications. Using the same embedding procedure, we also identify the string and brane representations that should be present in the spectrum.

hep-th↗

arXiv2025

The Boundary of Symmetric Moduli Spaces and the Swampland Distance Conjecture

For non-compact, locally symmetric moduli spaces M, the set of geodesics and the geometry of the boundary can be completely characterised using group theory. In particular, geodesics that asymptote to a given infinite distance boundary point are characterised by a choice of rational parabolic subgroup P(Q) of the local isometry group G and an element of the Cartan subalgebra of P(Q). Under the assumption that M satisfies the "compactifiability" constraint of arXiv:2412.03640 and some mild conditions on the spectrum of states, we use this formalism to prove the Swampland Distance Conjecture for essentially all locally symmetric spaces M. We show that the states necessarily transform in some representation of G, and further that the convex hull encoding the exponential rate at which the leading tower of states becomes light is simply the convex hull of the weights of the representation. In a companion paper, we then use the formalism to classify all locally symmetric spaces and irreducible representations that are consistent with the Emergent String Conjecture.

hep-th↗

arXiv2020

Smearing orientifolds in flux compactifications can be OK

We present explicit examples of supergravity solutions corresponding to backreacting localised (non-intersecting) O6 planes in flux reductions of massive IIA supergravity and address some criticism towards the very existence of such solutions. We verify in detail how the smeared orientifold solution becomes a good approximation to the localised solution in the large volume/weak coupling limit, as expected. We also find an exotic solution where prior to backreaction the internal space has a boundary and when backreaction is included the boundary disappears and the space closes off. The exotic example is however outside of the supergravity approximation everywhere.

hep-th↗

arXiv2019

Effective Field Theory Treatment of Monopole Production by Drell-Yan and Photon Fusion for Various Spins

A resolution over the existence of magnetic charges has eluded the high energy physics community for centuries, and their search has gained momentum as recent models predict these may be observable at current colliders. They appear in field theories in two forms: the widely studied but heavily suppressed monopole with structure (soliton) and the not-so-well-covered point-like monopole. The latter was first proposed by Dirac as the source of a singular magnetic field and in effect symmetrises Maxwell's equations. Following this line of research, work by S. Baines et al. analysed these sources as matter fields that carry spins 0, $\frac{1}{2}$, or 1, in an effective field theory that is perturbative for monopoles produced at threshold where the coupling strength $g(β)$ is suppressed. All three cases are currently under investigation by the MoEDAL collaboration at CERN, and the theoretical expressions for kinematic distributions proposed in this work serve as guides to these searches. The cross section distributions in each case are derived from a \emph{U}(1) invariant gauge theory. It is not assumed that, like the electron, the monopole's magnetic moment is generated through spin interactions at minimal coupling, as it may be quite large. Instead, the analytical expressions in the spin $\frac{1}{2}$ and $1$ cases are kept completely general through the inclusion of a phenomenological parameter $κ$, related to the gyromagnetic ratio $g_R=1+κ$. In fact, the inclusion of this parameter gives the effective theory validity in the high energy limit if the magnetic coupling scales with the particle's velocity $β=\frac{v}{c}$.

hep-ph↗