14 research outputs found
Old and new vacua of 5D maximal supergravity
We look for critical points with U(2) residual symmetry in 5-dimensional
maximally supersymmetric gauged supergravity, by varying the embedding tensor,
rather than directly minimizing the scalar potential. We recover all previously
known vacua and we find four new vacua, with different gauge groups and
cosmological constants. We provide the first example of a maximal supergravity
model in having critical points with both positive and vanishing
cosmological constant. For each vacuum we also compute the full mass spectrum.
All results are analytic.Comment: 29 pages, 1 figure. v2 References adde
Instanton solution for Schwinger production of 't Hooft-Polyakov monopoles
We present the results of an explicit numerical computation of a novel instanton in Georgi-Glashow SU(2) theory. The instanton is physically relevant as a mediator of Schwinger production of ’t Hooft–Polyakov magnetic monopoles from strong magnetic fields. In weak fields, the pair production rate has previously been computed using the worldline approximation, which breaks down in strong fields due to the effects of finite monopole size. Using lattice field theory we have overcome this limit, including finite monopole size effects to all orders. We demonstrate that a full consideration of the internal monopole structure results in an enhancement to the pair production rate, and confirm earlier results that monopole production becomes classical at the Ambjørn-Olesen critical field strength
Challenges and opportunities in machine learning for geometry
Over the past few decades, the mathematical community has accumulated a significant amount of pure mathematical data, which has been analyzed through supervised, semi-supervised, and unsupervised machine learning techniques with remarkable results, e.g., artificial neural networks, support vector machines, and principal component analysis. Therefore, we consider as disruptive the use of machine learning algorithms to study mathematical structures, enabling the formulation of conjectures via numerical algorithms. In this paper, we review the latest applications of machine learning in the field of geometry. Artificial intelligence can help in mathematical problem solving, and we predict a blossoming of machine learning applications during the next years in the field of geometry. As a contribution, we propose a new method for extracting geometric information from the point cloud and reconstruct a 2D or a 3D model, based on the novel concept of generalized asymptotes.Agencia Estatal de InvestigaciĂł
Three-dimensional flux vacua from IIB on co-calibrated G2 orientifolds
We derive the 3D N=1 superpotential for the closed string sector of type IIB
supergravity on toroidal O5 orientifolds with co-calibrated G2 structure and RR
background flux. We find that such compactifications can provide full closed
string moduli stabilization on supersymmetric AdS vacua, and once we
include brane-supersymmetry-breaking we also find indication for the existence
of classical 3D de Sitter solutions. The latter however are rather difficult to
reconcile with the shape moduli stabilization and flux quantization. We also
discuss the possibility of achieving scale separation in AdS and dS
vacua, but such effects seems to be hindered by the geometric flux
quantization.Comment: 38 page