Johannes Hirn

• University of Valencia

Urban traffic congestion is a critical issue with significant implications for mobility and urban planning. In this study, we develop a real-time predictive alarm system capable of forecasting whether a street is likely to experience unusually high traffic within the next 30 min. The system classifies road segments into three alert levels based on...

Traffic congestion represents a significant urban challenge, with notable implications for public health and environmental well‐being. Consequently, urban decision‐makers prioritize the mitigation of congestion. This study delves into the efficacy of harnessing extensive data on urban traffic dynamics, coupled with comprehensive knowledge of road n...

We aim to investigate how closely neural networks (NNs) mimic human thinking. As a step in this direction, we study the behavior of artificial neuron(s) that fire most when the input data score high on some specific emergent concepts. In this paper, we focus on music, where the emergent concepts are those of rhythm, pitch and melody as commonly use...

Urban traffic emissions represent a significant concern due to their detrimental impacts on both public health and the environment. Consequently, decision-makers have flagged their reduction as a crucial goal. In this study, we first analyze the correlation between traffic flux and pollution in the city of Valencia, Spain. Our results demonstrate t...

We use Google's MusicVAE, a Variational Auto-Encoder with a 512-dimensional latent space to represent a few bars of music, and organize the latent dimensions according to their relevance in describing music. We find that, on average, most latent neurons remain silent when fed real music tracks: we call these "noise" neurons. The remaining few dozen...

Traffic congestion is a major urban issue due to its adverse effects on health and the environment, so much so that reducing it has become a priority for urban decision-makers. In this work, we investigate whether a high amount of data on traffic flow throughout a city and the knowledge of the road city network allows an Artificial Intelligence to...

We explore whether Neural Networks (NNs) can {\it discover} the presence of symmetries as they learn to perform a task. For this, we train hundreds of NNs on a {\it decoy task} based on well-controlled Physics templates, where no information on symmetry is provided. We use the output from the last hidden layer of all these NNs, projected to fewer d...

We explore whether Neural Networks (NNs) can {\it discover} the presence of symmetries as they learn to perform a task. For this, we train hundreds of NNs on a {\it decoy task} based on well-controlled Physics templates, where no information on symmetry is provided. We use the output from the last hidden layer of all these NNs, projected to fewer d...

We construct an effective lagrangian for new strong interactions at the LHC, including as a first step the two lightest triplets of spin-1 resonances. Our parametrization is general enough to allow for previously unstudied spectrum and couplings. Among available frameworks to describe the spin-1 sector, we rely on an extra-dimensional description....

We present a collection of signatures for physics beyond the standard model that need to be explored at the LHC. The signatures are organized according to the experimental objects that appear in the final state, and in particular the number of high pT leptons. Our report, which includes brief experimental and theoretical reviews as well as original...

New strong interactions at the LHC may exhibit a richer structure than expected from simply rescaling QCD to the electroweak scale. In fact, a departure from rescaled QCD is required for compatibility with electroweak constraints. To navigate the space of possible scenarios, we use a simple framework, based on a 5D model with modifications of AdS g...

Models in extra dimensions have unique features. Many of their surprising properties simply result from the underlying 5D structure. This structure shows up as “sum rules” involving the whole tower of Kaluza-Klein factors. In this paper, we present a holographic shortcut and derive these results without solving the eigenvalue problem: we express 4D...

In this talk, an SU(Nf)xSU(Nf)Yang-Mills model with a compact extra-dimension is used to describe the spin-1 mesons and pions of massless QCD in the large-Nc. The right 4D symmetry and symmetry-breaking pattern is produced by imposing appropriate boundary conditions. The Goldstone boson fields are constructed using a Wilson line. We derive the low-...

We present a mechanism to get S ~ 0 or even negative, without bringing into play the SM fermion sector. This mechanism can be applied to a wide range of 5D models, including composite Higgs and Higgsless models. As a realization of the mechanism we introduce a simple model, although the effect on S does not rely on the underlying dynamics generatin...

We present a mechanism to get S ~ 0 or even negative, without bringing into play the SM fermion sector. This mechanism can be applied to a wide range of 5D models, including composite Higgs and Higgsless models. As a realization of the mechanism we introduce a simple model, although the effect on S does not rely on the underlying dynamics generatin...

We present a new class of 5D models, Holographic Technicolor, which fulfills the basic requirements for a candidate of comprehensible 4D strong dynamics at the electroweak scale. It is the first Technicolor-like model able to provide a vanishing or even negative tree-level S parameter, avoiding any no-go theorem on its sign. The model is described...

Following previous work, we identify a symmetry Snat that generalizes the concept of custodial symmetry, keeping under control deviations from the standard model (SM). To realize Snat linearly, the space of gauge fields has to be extended. Covariant constraints formulated in terms of spurions reduce Snat back to SU(2)L×U(1)Y. This allows for a cova...

An SU(Nf)xSU(Nf) Yang-Mills theory on an extra-dimensional interval is considered, with appropriate symmetry-breaking boundary conditions on the IR brane. UV-brane to UV-brane correlators at high energies are compared with the OPE of two-point functions of QCD quark currents. Condensates correspond to departure from AdS of the (different) metrics f...

In this talk, we describe an effective theory for electroweak symmetry breaking without a physical Higgs, based on a symmetry larger than the electroweak gauge group. This symmetry forbids deviations from the Standard Model at the leading order in the appropriate chiral expansion. Indeed, the large symmetry allows for a consistent expansion of the...

We describe the Goldstone bosons of massless QCD together with an infinite number of spin-1 mesons. The field content of the model is SU(Nf)xSU(Nf) Yang-Mills in a compact extra-dimension. Electroweak interactions reside on one brane. Breaking of chiral symmetry occurs due to the boundary conditions on the other brane, away from our world, and is t...

Following previous work, we identify a symmetry S_nat that generalizes the concept of custodial symmetry, keeping under control deviations from the Standard Model (SM). To realize S_nat linearly, the space of gauge fields has to be extended. Covariant constraints formulated in terms of spurions reduce S_nat back to SU(2)_L x U(1)_Y. This allows for...

The low-energy effective theory of electroweak symmetry-breaking without a Higgs particle is constructed using the methods of Chiral Perturbation Theory. Weinberg's power-counting formula demonstrates the consistency of the loop expansion, with the corresponding renormalization. We find that the suppression of effective operators by a mass scale, w...

We reconsider the low-energy effective theory for Higgs-less electroweak symmetry breaking: we study the anomaly-matching in the situation where all Goldstone fields disappear from the spectrum as a result of the Higgs mechanism. We find that the global SU(2)_L x SU(2)_R x U(1)_{B-L} symmetry of the underlying theory, which is spontaneously broken...

Inspired by recent developments of moose models, we reconsider low-energy effective theories of Goldstone bosons, gauge fields and chiral fermions applied to low-energy QCD and to Higgs-less electroweak symmetry breaking. Couplings and the corresponding reduction of symmetry are introduced via constraints enforced by a set of non-propagating covari...

La théorie effective à basse énergie du secteur électrofaible sans particule de Higgs utilise les méthodes de la Théorie de perturbation Chirale. La formule de comptage de Weinberg permet un développement cohérent en boucles et la renormalisation correspondante. On trouve que certains opérateurs effectifs, supprimés par une échelle de masse dans le...