Paper defines and analyzes Chillingworth classes for subsurface Torelli groups.
problem Understanding Chillingworth classes for subsurface Torelli groups.
method Combinatorial description and proof of properties of the Chillingworth class.
result Relates Chillingworth class to partitioned Johnson homomorphism.
Random subsurfaces of hyperbolic surfaces equidistribute to ribbon graphs.
problem Distribution of shapes of complementary subsurfaces in moduli space.
method Study of shapes of complementary subsurfaces in moduli space as boundary lengths go to infinity.
result Random subsurfaces look like random ribbon graphs.
The paper introduces the spirality character of the almost fiber part for a closed essentially immersed subsurface of a closed orientable aspherical 3-manifold, which generalizes an invariant due to Rubinstein and Wang. The subsurface is virtually embedded if and only if the almost fiber part is aspiral, and in this ca…
Study on compact and finite-type support in mapping class group homology.
problem Understanding non-trivial classes supported on compact or finite-type subsurfaces.
method Use of shiftable subsurfaces and homological stability for finite-type surfaces.
result Almost-complete answer for surfaces with positive genus, partial answer for zero genus.
Efficiently quantifies uncertainty in subsurface flow using neural networks guided by theory.
problem Uncertainty in dynamic subsurface flow predictions.
method Theory-guided Neural Network (TgNN) for efficient uncertainty quantification.
result TgNN surrogate improves efficiency of uncertainty quantification compared to MC method.
Subsurface applications including geothermal, geological carbon sequestration, oil and gas, etc., typically involve maximizing either the extraction of energy or the storage of fluids. Characterizing the subsurface is extremely complex due to heterogeneity and anisotropy. Due to this complexity, there are uncertainties…
SAGE generates subsurface velocity models from sparse well logs and seismic images.
problem Lack of high-quality subsurface velocity models due to limited data availability.
method Subsurface AI-driven geostatistical extraction using proxy posterior.
result SAGE produces geologically plausible and statistically accurate velocity realizations.
Proves Congruence Subgroup Property for two types of groups.
problem Proving Congruence Subgroup Property for specific groups.
method Elementary proof of Johnson filtration and geometric subsurface inclusions.
result Proves Congruence Subgroup Property for nilpotent quotients and subsurface subgroups.
Study arcs on surfaces, focusing on topological aspects and group actions.
problem Understanding arcs and their complements on surfaces.
method Characterize infinite-type surfaces via homeomorphic subsurfaces, construct actions on arc graphs.
result New characterisation of infinite-type surfaces and actions on arc graphs.
Combines deep generative models with ensemble methods for subsurface property estimation.
problem Estimating spatially distributed subsurface properties from sparse measurements.
method Wasserstein Generative Adversarial Network (WGAN-GP) and Ensemble Smoother with Multiple Data Assimilation (ES-MDA).
result The proposed method outperforms variational inversion methods, especially for channelized and fractured fields.
This paper is a study of the subgroups of the mapping class groups of Riemann surfaces, called "geometric" subgroups, corresponding to the inclusion of subsurfaces. Our analysis includes surfaces with boundary and with punctures. The centres of all the mapping class groups are calculated. We determine the kernel of inc…
Let M be a surface (possibly nonorientable) with punctures and/or boundary components. The paper is a study of ``geometric subgroups'' of the mapping class group of M, that is subgroups corresponding to inclusions of subsurfaces (possibly disconnected). We characterise the subsurfaces which lead to virtually abelian ge…
We compare the flat geometry associated to a quadratic differential with the hyperbolic geometry associated to the underlying Riemann surface. We show that if a curve is contained in a thick subsurface, then its hyperbolic length is comparable to its flat length times the flat size of the subsurface.
The study finds abundant normal generators for mapping class groups.
problem Understanding normal generation in mapping class groups.
method Analyzing restrictions on invariant subsurfaces and Teichmüller spaces.
result Reducible mapping classes can normally generate mapping class groups based on their asymptotic translation lengths.
Homological stability for mapping class groups on fixed subsurfaces.
problem Stability of mapping class groups on fixed subsurfaces.
method Study simplicial complexes formed by subsurfaces, generalize Hatcher-Vogtmann work.
result Prove homological stability theorems for specific mapping class groups.
New projection complex shows some surface homeomorphisms have positive commutator length.
problem Understanding commutator length in surface homeomorphisms.
method Constructing unbounded quasi-trees and a new projection complex.
result Some surface homeomorphisms have positive stable commutator length.
This paper has two main goals. First, we give a complete, explicit, and computable solution to the problem of when two simple closed curves on a surface are equivalent under the Johnson kernel. Second, we show that the Johnson filtration and the Johnson homomorphism can be defined intrinsically on subsurfaces and prove…
SPID-GAN learns bidirectional mappings in subsurface models.
problem Challenges in identifying and approximating causal structures in high-dimensional parameter spaces.
method Generative adversarial networks (GANs) for learning cross-domain mappings.
result SPID-GAN achieves satisfactory performance in identifying bidirectional state-parameter mappings.
We study the connections between subsurface projections in curve and arc complexes in fibered 3-manifolds and Agol's veering triangulation. The main theme is that large-distance subsurfaces in fibers are associated to large simplicial regions in the veering triangulation, and this correspondence holds uniformly for all…
New bound on sliding circuit set size in braid groups.
problem Bounding the size of sliding circuit sets in braid groups.
method Constructing examples of braids with multiple subsurfaces to suggest a geometric property.
result Found a family of braids with a sliding circuit set of at most C⋅LN−2 elements, suggesting a geometric property. Formula for projecting geodesics in hyperbolic 3-manifolds, relating lengths to subsurface projections.
problem Relating lengths of geodesics to projections in hyperbolic 3-manifolds.
method Formula with explicit constants relating subsurface projections to geodesic lengths.
result Effective and computable large projections versus short curves relation.
Study curves' intersections and distances, with applications in graph and group studies.
problem Understanding intersections and distances of curves.
method Using a relationship between intersection numbers and subsurface projection distances, applications in curve graphs and mapping class groups.
result Explicit quasi-constants for the relationship between intersection numbers and subsurface projection distances.
Generative adversarial networks improve stochastic input parametrization in subsurface flow simulations.
problem Effective parametrization of high-dimensional, correlated stochastic inputs in subsurface flow simulations.
method Training a generative adversarial network to emulate the data generating process of stochastic inputs.
result Generative adversarial networks preserve both visual realism and high-order statistics of flow responses, achieving a significant dimensionality reduction.
New graphs show hierarchical hyperbolic properties, extending previous work.
problem Characterizing hierarchically hyperbolic properties of multiarc and curve graphs.
method Analyzing the geometric intersection number and using PMod(S) action.
result Multiarc and curve graphs are hierarchically hyperbolic.
Study classifies mapping class groups with hyperbolic actions on infinite-type surfaces.
problem Classifying mapping class groups with hyperbolic actions on infinite-type surfaces.
method Analyzing curve graphs and their translates to construct hyperbolic spaces.
result Classification of mapping class groups with hyperbolic actions.
Graphs of multicurves are hyperbolic, relatively hyperbolic, or thick.
problem Characterizing graphs of multicurves based on their geometric properties.
method Proving graphs of multicurves are hyperbolic, relatively hyperbolic, or thick based on subsurface intersections.
result Geometric characterization of graphs of multicurves.
PIML enhances machine learning for subsurface energy systems.
problem Lack of interpretability and domain-specific knowledge in machine learning models.
method Integrates physics principles into data-driven models using deep learning.
result PIML improves model generalization and adherence to physical laws.
SURGIN uses generative models to infer subsurface flow data efficiently.
problem Inefficient and task-specific inversion methods for subsurface multiphase flow.
method SURGIN integrates U-FNO surrogate with SGM for zero-shot conditional generation.
result Decent inference of heterogeneous geological fields and flow dynamics with uncertainty quantification.
We show that the subsurface projection of a train track splitting sequence is an unparameterized quasi-geodesic in the curve complex of the subsurface. For the proof we introduce induced tracks, efficient position, and wide curves. This result is an important step in the proof that the disk complex is Gromov hyperbolic…
Proves conjecture about surface cover homology.
problem Proving Putman-Wieland conjecture about surface covers.
method Analyzes homology classes of curves and subsurfaces.
result Generates homology of covers by specific curve lifts.
Uniform bound on geodesic images for surfaces using bicorn curves.
problem Bounding geodesic images on closed surfaces.
method Utilizing bicorn curves and properties of 1-slim triangles.
result Uniform bound of 44 for non-annular subsurfaces, 3 for specific cases.
The article studies Hamiltonian flows on surface group representations induced by invariant multi-functions.
problem Hamiltonian flows on surface group representations induced by invariant multi-functions.
method Introducing subsurface deformation and proving Poisson commutativity of induced invariant multi-functions.
result Hamiltonian flows on character varieties are of subsurface deformation type and Poisson commute if supporting subsurfaces are disjoint.
TgNN improves neural network accuracy for subsurface flow modeling.
problem Improving accuracy of neural network predictions for subsurface flow.
method Theory-guided Neural Network (TgNN) trained with data and physical constraints.
result TgNN achieves higher accuracy and better generalizability than ANN models.
Method constructs WP geodesics to study Teichmüller space behavior.
problem Understanding behavior of WP geodesics in Teichmüller space.
method Constructs WP geodesics with specific properties.
result Demonstrates disparity between geodesics and hyperbolic 3-manifold curves.
We give a new proof of a celebrated theorem of Dennis Johnson that asserts that the kernel of the Johnson homomorphism on the Torelli subgroup of the mapping class group is generated by separating twists. In fact, we prove a more general result that also applies to "subsurface Torelli groups". Using this, we extend Joh…
Tackles dynamic subsurface flow via GAN with physical theory constraints.
problem Deep learning of dynamic subsurface flow with heterogeneous parameters.
method Theory-guided generative adversarial network (TgGAN) for PDEs.
result TgGAN predicts future subsurface flow responses robustly and efficiently.
Physics-informed GANs model subsurface flow at the Hanford Site.
problem Uncertainty quantification for subsurface flow modeling at the Hanford Site.
method Physics-informed GANs, hierarchical domain parallelism, multiple GPUs, efficient communication.
result Highly scalable physics-informed GANs model subsurface flow on Summit supercomputer.
Generative adversarial networks improve geological model generation.
problem Capturing complex geological structures in subsurface models.
method Wasserstein GAN for parametrization and generation of geological models.
result GANs preserve multipoint statistical features of geological models.
Paper tackles extension problem for surface diffeomorphisms.
problem Determining when a subsurface diffeomorphism can be extended to a whole surface.
method Analyzes two homology groups and a difference map for extensions.
result Extension problem depends on subsurface position but in a controlled way.
Physics-informed neural networks improve subsurface transport parameter estimation from sparse data.
problem Estimating subsurface transport parameters from sparse measurements.
method Physics-informed neural networks (DNNs) for joint inversion of conductivity, hydraulic head, and concentration fields.
result Physics-informed DNNs yield significantly more accurate parameter estimates than standard DNNs.
Develops active intervals for geodesics in Teichmüller space.
problem Understanding geodesics in Teichmüller space with no backtracking.
method Defines active intervals for subsurfaces along geodesics in Thurston metric.
result Active intervals represent reparametrized quasi-geodesics in curve graphs with bounded movement outside.
Growth rates of geodesics on modular orbifolds are studied.
problem Understanding growth rates of geodesics on modular orbifolds.
method Exhaustion of modular orbifold by compact subsurfaces, analysis of low lying geodesics and reciprocal geodesics.
result Growth rates of low lying geodesics and reciprocal geodesics converge to the full set's growth rate.
The curve graphs are not locally finite. In this paper, we show that the curve graphs satisfy a property which is equivalent to graphs being uniformly locally finite via Masur--Minsky's subsurface projections. As a direct application of this study, we show that there exist computable bounds for Bowditch's slices on tig…
Deep learning methods improve subsurface flow modeling efficiency.
problem Efficiently modeling subsurface flow with uncertain parameters.
method Two categories of deep-learning based inverse modeling methods: surrogate-based and direct.
result Deep-learning methods significantly accelerate subsurface flow modeling.
Johnson kernel generated by specific Dehn twists on surfaces.
problem Identifying the generating set of Johnson kernel for surfaces.
method Analyzing Dehn twists on specific types of surfaces.
result Johnson kernel generated by Dehn twists on specified surfaces.
Let M be a smooth connected compact surface and P be either a real line or a circle. This paper proceeds the study of the stabilizers and orbits of smooth functions on M with respect to the right action of the group of diffeomorphisms of M. A large class of smooth maps f:M→P with isolated singularities is …
Subsurface projection has become indispensable in studying the geometry of the mapping class group and the curve complex of a surface. When the subsurface is an annulus, this projection is sometimes called relative twisting. We give two alternate versions of relative twisting for the outer automorphism group of a free …
The paper simplifies 3-manifold decompositions using separating surfaces.
problem Decomposing 3-manifolds with Heegaard splittings.
method Using Morse position and separating incompressible surfaces.
result Simplifies the hierarchy of 3-manifolds.