25 citations · 86 across the 17 of their papers we have counts for
17 papers
Structured Gaussian Processes for Uncertainty-Aware Classification of High-Dimensional, Small-Sampled Omics Data
Yue Zhang, Nandini Amit Gadhia, Georgios Karagiannis +1
Classifying heterogeneous omics data remains a fundamental challenge in computational biology, particularly in high-dimensional, small-sample settings where nonlinear interactions…
Duality, generalized global symmetries and jet space isometries
Athanasios Chatzistavrakidis, Georgios Karagiannis, Arash Ranjbar
We revisit universal features of duality in linear and nonlinear relativistic scalar and Abelian 1-form theories with single or multiple fields, which exhibit ordinary or generaliz…
Axion gravitodynamics, Lense-Thirring effect, and gravitational waves
Athanasios Chatzistavrakidis, Georgios Karagiannis, George Manolakos +1
We investigate physical implications of a gravitational analog of axion electrodynamics with a parity-violating gravitoelectromagnetic theta term. This is related to the Nieh-Yan t…
Tensor Galileons as Lovelock theories
Georgios Karagiannis
We review the construction of Galileon interactions involving a single two-column mixed-symmetry tensor of arbitrary degree in flat spacetime of arbitrary dimensions, in a reverse…
Duality and higher Buscher rules in p-form gauge theory and linearized gravity
Athanasios Chatzistavrakidis, Georgios Karagiannis, Arash Ranjbar
We perform an in-depth analysis of the transformation rules under duality for couplings of theories containing multiple scalars, -form gauge fields, linearized gravitons or $(p,…
Accelerating Convergence of Replica Exchange Stochastic Gradient MCMC via Variance Reduction
Wei Deng, Qi Feng, Georgios Karagiannis +2
Replica exchange stochastic gradient Langevin dynamics (reSGLD) has shown promise in accelerating the convergence in non-convex learning; however, an excessively large correction f…
Torsion-induced gravitational term and gravitoelectromagnetism
Athanasios Chatzistavrakidis, Georgios Karagiannis, Peter Schupp
Motivated by the analogy between a weak field expansion of general relativity and Maxwell's laws of electrodynamics, we explore physical consequences of a parity violating term…
Graded Geometry and Tensor Gauge Theories
Athanasios Chatzistavrakidis, Georgios Karagiannis, Peter Schupp
We review the construction of Lagrangians for higher spin fields of mixed symmetry in the framework of graded geometry. The main advantage of the graded formalism in this context i…
Hierarchical Bayesian Nearest Neighbor Co-Kriging Gaussian Process Models; An Application to Intersatellite Calibration
Si Cheng, Bledar A. Konomi, Jessica L. Matthews +2
Recent advancements in remote sensing technology and the increasing size of satellite constellations allows massive geophysical information to be gathered daily on a global scale b…
Relation between standard and exotic duals of differential forms
Athanasios Chatzistavrakidis, Georgios Karagiannis
Exotic duality suggests a link between gauge theories for differential p-forms and tensor fields of mixed symmetry [D-2,p] in D spacetime dimensions. On the other hand, standard Ho…
Inverse modeling of hydrologic parameters in CLM4 via generalized polynomial chaos in the Bayesian framework
Georgios Karagiannis, Zhangshuan Hou, Maoyi Huang +1
In this study, the applicability of generalized polynomial chaos (gPC) expansion for land surface model parameter estimation is evaluated. We compute the (posterior) distribution o…
Bayesian analysis of multifidelity computer models with local features and non-nested experimental designs: Application to the WRF model
Bledar A. Konomi, Georgios Karagiannis
We propose a multi-fidelity Bayesian emulator for the analysis of the Weather Research and Forecasting (WRF) model when the available simulations are not generated based on hierarc…
Multifidelity Computer Model Emulation with High-Dimensional Output: An Application to Storm Surge
Pulong Ma, Georgios Karagiannis, Bledar A. Konomi +3
Hurricane-driven storm surge is one of the most deadly and costly natural disasters, making precise quantification of the surge hazard of great importance. Surge hazard quantificat…
A unified approach to standard and exotic dualizations through graded geometry
Athanasios Chatzistavrakidis, Georgios Karagiannis, Peter Schupp
Gauge theories can often be formulated in different but physically equivalent ways, a concept referred to as duality. Using a formalism based on graded geometry, we provide a unifi…
Ice Model Calibration Using Semi-continuous Spatial Data
Won Chang, Bledar A. Konomi, Georgios Karagiannis +2
Rapid changes in Earth's cryosphere caused by human activity can lead to significant environmental impacts. Computer models provide a useful tool for understanding the behavior and…
On the Bayesian calibration of expensive computer models with input dependent parameters
Georgios Karagiannis, Bledar A. Konomi, Guang Lin
Computer models, aiming at simulating a complex real system, are often calibrated in the light of data to improve performance. Standard calibration methods assume that the optimal…
Parallel and Interacting Stochastic Approximation Annealing algorithms for global optimisation
Georgios Karagiannis, Bledar A. Konomi, Guang Lin +1
We present the parallel and interacting stochastic approximation annealing (PISAA) algorithm, a stochastic simulation procedure for global optimisation, that extends and improves t…