Skip to main content

Research Repository

Advanced Search

All Outputs (222)

Causality in heliophysics: Magnetic fields as a bridge between the Sun’s interior and the Earth’s space environment (2023)
Journal Article
Nandy, D., Baruah, Y., Bhowmik, P., Dash, S., Gupta, S., Hazra, S., …Sinha, S. (2023). Causality in heliophysics: Magnetic fields as a bridge between the Sun’s interior and the Earth’s space environment. Journal of Atmospheric and Solar-Terrestrial Physics, 248, Article 106081. https://doi.org/10.1016/j.jastp.2023.106081

Our host star, the Sun, is a middle-aged main sequence G type star whose activity varies. These variations are primarily governed by solar magnetic fields which are produced in the Sun’s interior via a magnetohydrodynamic dynamo mechanism. Solar acti... Read More about Causality in heliophysics: Magnetic fields as a bridge between the Sun’s interior and the Earth’s space environment.

A generalized system reliability model based on survival signature and multiple competing failure processes (2023)
Journal Article
Chang, M., Coolen, F., Coolen-Maturi, T., & Huang, X. (2023). A generalized system reliability model based on survival signature and multiple competing failure processes. Journal of Computational and Applied Mathematics, Article 115364. https://doi.org/10.1016/j.cam.2023.115364

Degradation-based system reliability analysis has been extensively conducted, but the components in a system are assumed to experience similar degradation and shock processes, neglecting actual failure mechanisms. However, multiple types of component... Read More about A generalized system reliability model based on survival signature and multiple competing failure processes.

Symmetry TFTs from String Theory (2023)
Journal Article
Apruzzi, F., Bonetti, F., García Etxebarria, I., Hosseini, S. S., & Schäfer-Nameki, S. (2023). Symmetry TFTs from String Theory. Communications in Mathematical Physics, 402(1), 895-949. https://doi.org/10.1007/s00220-023-04737-2

We determine the d+1 dimensional topological field theory, which encodes the higher-form symmetries and their ’t Hooft anomalies for d-dimensional QFTs obtained by compactifying M-theory on a non-compact space X. The resulting theory, which we call t... Read More about Symmetry TFTs from String Theory.

Stabilization estimates for the Brinkman–Forchheimer–Kelvin–Voigt equation backward in time (2023)
Journal Article
Gentile, M., & Straughan, B. (2023). Stabilization estimates for the Brinkman–Forchheimer–Kelvin–Voigt equation backward in time. Acta Mechanica, 234(9), 4001-4009. https://doi.org/10.1007/s00707-023-03592-5

The final value value problem for the Brinkman–Forchheimer–Kelvin–Voigt equations is analysed for quadratic and cubic types of Forchheimer nonlinearity. The main term in the Forchheimer equations is allowed to be fully anisotropic. It is shown that t... Read More about Stabilization estimates for the Brinkman–Forchheimer–Kelvin–Voigt equation backward in time.

Optimal Control of Probability on A Target Set for Continuous-Time Markov Chains (2023)
Journal Article
Ma, C., & Zhao, H. (2023). Optimal Control of Probability on A Target Set for Continuous-Time Markov Chains. IEEE Transactions on Automatic Control, https://doi.org/10.1109/tac.2023.3278789

In this paper, a stochastic optimal control problem is considered for a continuous-time Markov chain taking values in a denumerable state space over a fixed finite horizon. The optimality criterion is the probability that the process remains in a tar... Read More about Optimal Control of Probability on A Target Set for Continuous-Time Markov Chains.

Surface Flux Transport on the Sun (2023)
Journal Article
Yeates, A., Cheung, M., Jiang, J., Petrovay, K., & Wang, Y. (2023). Surface Flux Transport on the Sun. Space Science Reviews, https://doi.org/10.1007/s11214-023-00978-8

We review the surface flux transport model for the evolution of magnetic flux patterns on the Sun’s surface. Our underlying motivation is to understand the model’s prediction of the polar field (or axial dipole) strength at the end of the solar cycle... Read More about Surface Flux Transport on the Sun.

Spherical winding and helicity (2023)
Journal Article
Xiao, D., Prior, C., & Yeates, A. (2023). Spherical winding and helicity. Journal of Physics A: Mathematical and Theoretical, 56(20), Article 205201. https://doi.org/10.1088/1751-8121/accc17

In ideal magnetohydrodynamics, magnetic helicity is a conserved dynamical quantity and a topological invariant closely related to Gauss linking numbers. However, for open magnetic fields with non-zero boundary components, the latter geometrical inter... Read More about Spherical winding and helicity.

Consistent truncations from the geometry of sphere bundles (2023)
Journal Article
Bonetti, F., Minasian, R., Camell, V. V., & Weck, P. (2023). Consistent truncations from the geometry of sphere bundles. Journal of High Energy Physics, 2023(5), Article 156. https://doi.org/10.1007/jhep05%282023%29156

In this paper, we present a unified perspective on sphere consistent truncations based on the classical geometric properties of sphere bundles. The backbone of our approach is the global angular form for the sphere. A universal formula for the Kaluza... Read More about Consistent truncations from the geometry of sphere bundles.

On the asymptotic behavior of solutions to a class of grand canonical master equations (2023)
Journal Article
Vuillermot, P., & Bögli, S. (2023). On the asymptotic behavior of solutions to a class of grand canonical master equations. Portugaliae Mathematica, 80(3), 269-289. https://doi.org/10.4171/pm/2102

In this article, we investigate the long-time behavior of solutions to a class of infinitely many master equations defined from transition rates that are suitable for the description of a quantum system approaching thermodynamical equilibrium with a... Read More about On the asymptotic behavior of solutions to a class of grand canonical master equations.

Embedded surfaces with infinite cyclic knot group (2023)
Journal Article
Conway, A., & Powell, M. (2023). Embedded surfaces with infinite cyclic knot group. Geometry & Topology, 27(2), 739-821. https://doi.org/10.2140/gt.2023.27.739

We study locally flat, compact, oriented surfaces in 4-manifolds whose exteriors have infinite cyclic fundamental group. We give algebraic topological criteria for two such surfaces, with the same genus g, to be related by an ambient homeomorphism, a... Read More about Embedded surfaces with infinite cyclic knot group.

Anosov groups: local mixing, counting and equidistribution (2023)
Journal Article
Edwards, S., Lee, M., & Oh, H. (2023). Anosov groups: local mixing, counting and equidistribution. Geometry & Topology, 27(2), 513-573. https://doi.org/10.2140/gt.2023.27.513

Let G be a connected semisimple real algebraic group, and Γ<G a Zariski dense Anosov subgroup with respect to a minimal parabolic subgroup. We describe the asymptotic behavior of matrix coefficients ⟨(exptv). f1,f2⟩ in L2(Γ∖G) as t→∞ for any f1,f2Cc(...

The Asymptotic Statistics of Random Covering Surfaces (2023)
Journal Article
Magee, M., & Puder, D. (2023). The Asymptotic Statistics of Random Covering Surfaces. Forum of mathematics. Pi, 11, Article e15. https://doi.org/10.1017/fmp.2023.13

Let Γg be the fundamental group of a closed connected orientable surface of genus g ≥ 2. We develop a new method for integrating over the representation space Xg,n = Hom(Γg, Sn) where Sn is the symmetric group of permutations of {1, . . . , n}. Equiv... Read More about The Asymptotic Statistics of Random Covering Surfaces.

Removable sets and Lp-uniqueness on manifolds and metric measure spaces (2023)
Journal Article
Hinz, M., Masamune, J., & Suzuki, K. (2023). Removable sets and Lp-uniqueness on manifolds and metric measure spaces. Nonlinear Analysis: Theory, Methods and Applications, 234, https://doi.org/10.1016/j.na.2023.113296

We study symmetric diffusion operators on metric measure spaces. Our main question is whether essential self-adjointness or -uniqueness are preserved under the removal of a small closed set from the space. We provide characterizations of the critical... Read More about Removable sets and Lp-uniqueness on manifolds and metric measure spaces.

Thermal fluctuations of black holes with non-linear electrodynamics and charged Renyi entropy (2023)
Journal Article
Arenas-Henriquez, G., Diaz, F., & Novoa, Y. (2023). Thermal fluctuations of black holes with non-linear electrodynamics and charged Renyi entropy. Journal of High Energy Physics, 2023(5), Article 72. https://doi.org/10.1007/jhep05%282023%29072

We extend the charged Renyi entropy to a more general holographic scenario. Coupling an arbitrary non-linear electrodynamics Lagrangian density to AdS gravity, we analyse the thermodynamic features of non-linearly charged hyperbolic black holes and t... Read More about Thermal fluctuations of black holes with non-linear electrodynamics and charged Renyi entropy.

Resurgence in 2-dimensional Yang–Mills and a genus-altering deformation (2023)
Journal Article
Fujimori, T., & Glass, P. (2023). Resurgence in 2-dimensional Yang–Mills and a genus-altering deformation. Progress of Theoretical and Experimental Physics, 2023(5), Article 053B03. https://doi.org/10.1093/ptep/ptad058

We study resurgence in the context of the partition function of 2-dimensional SU(N) and U(N) Yang–Mills theory on a surface of genus h. After discussing the properties of the transseries in the undeformed theory, we add a term to the action to deform... Read More about Resurgence in 2-dimensional Yang–Mills and a genus-altering deformation.

Lattice quantum Villain Hamiltonians: compact scalars, U(1) gauge theories, fracton models and quantum Ising model dualities (2023)
Journal Article
Fazza, L., & Sulejmanpasic, T. (2023). Lattice quantum Villain Hamiltonians: compact scalars, U(1) gauge theories, fracton models and quantum Ising model dualities. Journal of High Energy Physics, 2023(5), Article 17. https://doi.org/10.1007/jhep05%282023%29017

We construct Villain Hamiltonians for compact scalars and abelian gauge theories. The Villain integers are promoted to integral spectrum operators, whose canonical conjugates are naturally compact scalars. Further, depending on the theory, these conj... Read More about Lattice quantum Villain Hamiltonians: compact scalars, U(1) gauge theories, fracton models and quantum Ising model dualities.

The impact of alternative delivery strategies for novel tuberculosis vaccines in low-income and middle-income countries: a modelling study (2023)
Journal Article
Clark, R. A., Mukandavire, C., Portnoy, A., Weerasuriya, C. K., Deol, A., Scarponi, D., …White, R. G. (2023). The impact of alternative delivery strategies for novel tuberculosis vaccines in low-income and middle-income countries: a modelling study. The Lancet Global Health, 11(4), 546-555. https://doi.org/10.1016/s2214-109x%2823%2900045-1

Background
Tuberculosis is a leading infectious cause of death worldwide. Novel vaccines will be required to reach global targets and reverse setbacks resulting from the COVID-19 pandemic. We estimated the impact of novel tuberculosis vaccines in lo... Read More about The impact of alternative delivery strategies for novel tuberculosis vaccines in low-income and middle-income countries: a modelling study.

Massively parallel computation of tropical varieties, their positive part, and tropical Grassmannians (2023)
Journal Article
Bendle, D., Böhm, J., Ren, Y., & Schröter, B. (2023). Massively parallel computation of tropical varieties, their positive part, and tropical Grassmannians. Journal of Symbolic Computation, 120, https://doi.org/10.1016/j.jsc.2023.102224

We present a massively parallel framework for computing tropicalizations of algebraic varieties which can make use of symmetries using the workflow management system GPI-Space and the computer algebra system Singular. We determine the tropical Grassm... Read More about Massively parallel computation of tropical varieties, their positive part, and tropical Grassmannians.