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Imaging detection of the inner dust belt and the four exoplanets in the HR8799 system with JWST's MIRI coronagraph
(2023)arXivThe multi planet system HR8799 is the first target observed with MIRI's coronagraphs as part of the MIRI-EC Guaranteed Time Observations exoplanets programme in Nov. 2022. We obtained deep observations in three coronagraphic filters from 10 to 15mic (F1065C, F1140C, F1550C), and one standard imaging filter at 20 mic (F2100W), with the goal to extract the photometry of the four planets, as well as to detect and investigate the distribution ...Working Paper -
Orchestrated excitatory and inhibitory plasticity produces stable dynamics in heterogeneous neuromorphic computing systems
(2023)Research SquareMany neural computations emerge from self-sustained patterns of activity in recurrent neural circuits, which rely on balanced excitation and inhibition. Neuromorphic electronic circuits that use the physics of silicon to emulate neuronal dynamics represent a promising approach for implementing the brain's computational primitives, including self-sustained neural activity. However, achieving the same robustness of biological networks in ...Working Paper -
How accurate are neural approximations of complex network dynamics?
(2023)arXivData-driven approximations of ordinary differential equations offer a promising alternative to classical methods of discovering a dynamical system model, particularly in complex systems lacking explicit first principles. This paper focuses on a complex system whose dynamics is described with a system of such equations, coupled through a complex network. Numerous real-world systems, including financial, social, and neural systems, belong ...Working Paper -
The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems III: Aperture Masking Interferometric Observations of the star HIP 65426 at 3.8 μm
(2023)arXivWe present aperture masking interferometry (AMI) observations of the star HIP 65426 at $3.8\,\rm{μm}$ as a part of the \textit{JWST} Direct Imaging Early Release Science (ERS) program obtained using the Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument. This mode provides access to very small inner working angles (even separations slightly below the Michelson limit of ${}0.5λ/D$ for an interferometer), which are inaccessible ...Working Paper -
The Mixtures and the Neural Critics: On the Pointwise Mutual Information Profiles of Fine Distributions
(2023)arXivMutual information quantifies the dependence between two random variables and remains invariant under diffeomorphisms. In this paper, we explore the pointwise mutual information profile, an extension of mutual information that maintains this invariance. We analytically describe the profiles of multivariate normal distributions and introduce the family of fine distributions, for which the profile can be accurately approximated using Monte ...Working Paper -
Tensor Network Decoding Beyond 2D
(2023)arXivDecoding algorithms based on approximate tensor network contraction have proven tremendously successful in decoding 2D local quantum codes such as surface/toric codes and color codes, effectively achieving optimal decoding accuracy. In this work, we introduce several techniques to generalize tensor network decoding to higher dimensions so that it can be applied to 3D codes as well as 2D codes with noisy syndrome measurements (phenomenological ...Working Paper -
Recurrent models of orientation selectivity enable robust early-vision processing in mixed-signal neuromorphic hardware
(2023)Research SquareMixed signal analog/digital neuromorphic circuits represent an ideal medium for reproducing the dynamics of biological neural systems in real-time with bio-physically realistic dynamics. However, similar to their biological counterparts, these circuits have limited resolution and are affected by a high degree of variability. Considering this, we developed a recurrent spiking neural network that implements a faithful model of the retinocortical ...Working Paper -
Three-dimensional characterization of the steel-concrete interface by FIB-SEM nanotomography
(2023)arXivWhile it is widely accepted that the steel-concrete interface (SCI) plays an important role in governing the long-term durability of reinforced concrete structures, understanding about the primary features of the SCI that influence corrosion degradation mechanisms has remained elusive. This lack of knowledge can be attributed, on the one hand, to the complex heterogeneous nature of the SCI, and, on the other hand, the absence of experimental ...Working Paper -
Disentangling the Effects of Structure and Lone-Pair Electrons in the Lattice Dynamics of Halide Perovskites
(2023)arXivMetal halide perovskites have shown great performance as solar energy materials, but their outstanding optoelectronic properties are paired with unusually strong anharmonic effects. It has been proposed that this intriguing combination of properties derives from the "lone pair" electrons of the octahedral metal cations, but the precise impact of this chemical feature remains unclear. Here we show that in fact a lone pair of electrons is ...Working Paper -
Earth as an Exoplanet. III. Using Empirical Thermal Emission Spectra as Input for Atmospheric Retrieval of an Earth-Twin Exoplanet
(2023)arXivIn this study, we treat Earth as an exoplanet and investigate our home planet by means of a potential future mid-infrared (MIR) space mission called the Large Interferometer For Exoplanets (LIFE). We combine thermal spectra from an empirical dataset of disk-integrated Earth observations with a noise model for LIFE to create mock observations. We apply a state-of-the-art atmospheric retrieval framework to characterize the planet, assess ...Working Paper