
Goles, E., & Montealegre, P. (2020). The complexity of the asynchronous prediction of the majority automata. Inf. Comput., 274(SI).
Abstract: We consider the asynchronous prediction problem for some automaton as the one consisting in determining, given an initial configuration, if there exists a nonzero probability that some selected site changes its state, when the network is updated picking one site at a time uniformly at random. We show that for the majority automaton, the asynchronous prediction problem is in NC in the twodimensional lattice with von Neumann neighborhood. Later, we show that in three or more dimensions the problem is NPComplete.



Goles, E., Lobos, F., Ruz, G. A., & Sene, S. (2020). Attractor landscapes in Boolean networks with firing memory: a theoretical study applied to genetic networks. Nat. Comput., 19(2), 295–319.
Abstract: In this paper we study the dynamical behavior of Boolean networks with firing memory, namely Boolean networks whose vertices are updated synchronously depending on their proper Boolean local transition functions so that each vertex remains at its firing state a finite number of steps. We prove in particular that these networks have the same computational power than the classical ones, i.e. any Boolean network with firing memory composed of m vertices can be simulated by a Boolean network by adding vertices. We also prove general results on specific classes of networks. For instance, we show that the existence of at least one delay greater than 1 in disjunctive networks makes such networks have only fixed points as attractors. Moreover, for arbitrary networks composed of two vertices, we characterize the delay phase space, i.e. the delay values such that networks admits limit cycles or fixed points. Finally, we analyze two classical biological models by introducing delays: the model of the immune control of the lambda\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{69pt} \begin{document}$$\lambda $$\end{document}phage and that of the genetic control of the floral morphogenesis of the plant Arabidopsis thaliana.



Goles, E., Maldonado, D., Montealegre, P., & Ollinger, N. (2020). On the complexity of the stability problem of binary freezing totalistic cellular automata. Inf. Comput., 274, 21 pp.
Abstract: In this paper we study the family of twostate Totalistic Freezing Cellular Automata (TFCA) defined over the triangular and square grids with von Neumann neighborhoods. We say that a Cellular Automaton is Freezing and Totalistic if the active cells remain unchanged, and the new value of an inactive cell depends only on the sum of its active neighbors. We classify all the Cellular Automata in the class of TFCA, grouping them in five different classes: the Trivial rules, Turing Universal rules, Algebraic rules, Topological rules and Fractal Growing rules. At the same time, we study in this family the STABILITY problem, consisting in deciding whether an inactive cell becomes active, given an initial configuration. We exploit the properties of the automata in each group to show that: For Algebraic and Topological Rules the STABILITY problem is in NC. For Turing Universal rules the STABILITY problem is PComplete. (C) 2020 Elsevier Inc. All rights reserved.



Goles, E., Montealegre, P., & RiosWilson, M. (2020). On The Effects Of Firing Memory In The Dynamics Of Conjunctive Networks. Discret. Contin. Dyn. Syst., 40(10), 5765–5793.
Abstract: A boolean network is a map F : {0, 1}(n) > {0, 1}(n) that defines a discrete dynamical system by the subsequent iterations of F. Nevertheless, it is thought that this definition is not always reliable in the context of applications, especially in biology. Concerning this issue, models based in the concept of adding asynchronicity to the dynamics were propose. Particularly, we are interested in a approach based in the concept of delay. We focus in a specific type of delay called firing memory and it effects in the dynamics of symmetric (nondirected) conjunctive networks. We find, in the caseis in which the implementation of the delay is not uniform, that all the complexity of the dynamics is somehow encapsulated in the component in which the delay has effect. Thus, we show, in the homogeneous case, that it is possible to exhibit attractors of nonpolynomial period. In addition, we study the prediction problem consisting in, given an initial condition, determinate if a fixed coordinate will eventually change its state. We find again that in the nonhomogeneous case all the complexity is determined by the component that is affected by the delay and we conclude in the homogeneous case that this problem is PSPACEcomplete.



Goles, E., Tsompanas, M. A., Adamatzky, A., Tegelaar, M., Wosten, H. A. B., & Martinez, G. J. (2020). Computational universality of fungal sandpile automata. Phys. Lett. A, 384(22), 8 pp.
Abstract: Hyphae within the mycelia of the ascomycetous fungi are compartmentalised by septa. Each septum has a pore that allows for intercompartmental and interhyphal streaming of cytosol and even organelles. The compartments, however, have special organelles, Woronin bodies, that can plug the pores. When the pores are blocked, no flow of cytoplasm takes place. Inspired by the controllable compartmentalisation within the mycelium of the ascomycetous fungi we designed twodimensional fungal automata. A fungal automaton is a cellular automaton where communication between neighbouring cells can be blocked on demand. We demonstrate computational universality of the fungal automata by implementing sandpile cellular automata circuits there. We reduce the Monotone Circuit Value Problem to the Fungal Automaton Prediction Problem. We construct families of wires, crossovers and gates to prove that the fungal automata are Pcomplete. (C) 2020 Elsevier B.V. All rights reserved.



Golovach, P. A., Heggernes, P., Lima, P. T., & Montealegre, P. (2020). Finding connected secluded subgraphs. J. Comput. Syst. Sci., 113, 101–124.
Abstract: Problems related to finding induced subgraphs satisfying given properties form one of the most studied areas within graph algorithms. However, for many applications, it is desirable that the found subgraph has as few connections to the rest of the graph as possible, which gives rise to the SECLUDED PiSUBGRAPH problem. Here, input k is the size of the desired subgraph, and input t is a limit on the number of neighbors this subgraph has in the rest of the graph. This problem has been studied from a parameterized perspective, and unfortunately it turns out to be W[1]hard for many graph properties Pi, even when parameterized by k + t. We show that the situation changes when we are looking for a connected induced subgraph satisfying Pi. In particular, we show that the CONNECTED SECLUDED PiSUBGRAPH problem is FPT when parameterized by just t for many important graph properties Pi. (C) 2020 Elsevier Inc. All rights reserved.



Golovach, P. A., Heggernes, P., Lima, P. T., & Montealegre, P. (2020). Finding Connected Secluded Subgraphs. In 12th International Symposium on Parameterized and Exact Computation (Vol. 89, pp. 1–13).



Gonzalez, E., & Villena, M. J. (2020). On the spatial dynamics of vaccination: A spatial SIRSV model. Comput. Math. Appl., 80(5), 733–743.
Abstract: In this paper, we analyze the effects of vaccination from a spatial perspective. We propose a spatial deterministic SIRSV model, which considers a nonlinear system of partial differential equations with explicit attrition and diffusion terms for the vaccination process. The model allows us to simulate numerically the spatial and temporal dynamics of an epidemic, considering different spatial strategies for the vaccination policy. In particular, in our first example we analyze the classical SIRSV evolution with the addition of movements due to diffusion, while in the second one we focus on modeling one ring vaccination policy. We expect this model can improve spatial predictions of SIR vaccination models by taking into account the spatial dimension of the problem. (C) 2020 Elsevier Ltd. All rights reserved.



Gonzalez, H. A., Puhm, A.,, & Rojas, F. (2020). Loop corrections to celestial amplitudes. Phys. Rev. D., 102, 126027.
Abstract: We study the effect of loop corrections to conformal correlators on the celestial sphere at null infinity. We first analyze finite oneloop celestial amplitudes in pure YangMills theory and Einstein gravity. We then turn to our main focus: infrared divergent loop amplitudes in planar N=4
super–YangMills theory. We compute the celestial oneloop amplitude in dimensional regularization and show that it can be recast as an operator acting on the celestial treelevel amplitude. This extends to any loop order, and the resummation of all planar loops enables us to write down an expression for the allloop celestial amplitude. Finally, we show that the exponentiated allloop expression given by the BernDixonSmirnov (BDS) formula gets promoted on the celestial sphere to an operator acting on the treelevel conformal correlation function, thus yielding, the celestial BDS formula.



Gravelle, S., & Dumais, J. (2020). A multiscale model for fluid transport through a bioinspired passive valve. J. Chem. Phys., 152(1), 10 pp.
Abstract: Tillandsia landbeckii is a rootless plant thriving in the hyperarid Atacama Desert of Chile. These plants use unique cellulosebased microscopic structures called trichomes to collect fresh water from coastal fog. The trichomes rely on a passive mechanism to maintain an asymmetrical transport of water: they allow for the fast absorption of liquid water deposited by sporadic fog events while preventing evaporation during extended drought periods. Inspired by the trichome's design, we study fluid transport through a micrometric valve. Combining Grand Canonical Monte Carlo with NonEquilibrium Molecular Dynamics simulations, we first analyze the adsorption and transport of a fluid through a single nanopore at different chemical potentials. We then scale up the atomic results using a lattice approach, and simulate the transport at the micrometric scale. Results obtained for a model LennardJones fluid and TIP4P/2005 water were compared, allowing us to identify the key physical parameters for achieving a passive hydraulic valve. Our results show that the difference in transport properties of water vapor and liquid water within the cellulose layer is the basis for the ability of the Tillandsia trichome to function as a water valve. Finally, we predict a critical pore dimension above which the cellulose layer can form an efficient valve.



Guevara, E., Babonneau, F., HomemdeMello, T., & Moret, S. (2020). A machine learning and distributionally robust optimization framework for strategic energy planning under uncertainty. Appl. Energy, 271, 18 pp.
Abstract: This paper investigates how the choice of stochastic approaches and distribution assumptions impacts strategic investment decisions in energy planning problems. We formulate a twostage stochastic programming model assuming different distributions for the input parameters and show that there is significant discrepancy among the associated stochastic solutions and other robust solutions published in the literature. To remedy this sensitivity issue, we propose a combined machine learning and distributionally robust optimization (DRO) approach which produces more robust and stable strategic investment decisions with respect to uncertainty assumptions. DRO is applied to deal with ambiguous probability distributions and Machine Learning is used to restrict the DRO model to a subset of important uncertain parameters ensuring computational tractability. Finally, we perform an outofsample simulation process to evaluate solutions performances. The Swiss energy system is used as a case study all along the paper to validate the approach.



Guzman, R., Harrison, R., Abarca, N., & Villena, M. G. (2020). A gametheoretic model of reciprocity and trust that incorporates personality traits. J. Behav. Exp. Econ., 84, 11 pp.
Abstract: We propose a gametheoretic model of reciprocity and trust that incorporates personality traits. In the model, positive and negative reciprocity are “reciprocal preferences:” parameters of heterogeneous utility functions that take into account the material welfare of others (positively if they have been kind, negatively if they have been hostile). Trust, on the other hand, is an individual bias that distorts probabilistic beliefs about the trustworthiness of others. Unlike typical gametheoretic models, our model provides an explanation for the heterogeneity of preferences and probabilistic beliefs: a person's personality traits determine both the parameters of his utility function and the magnitude of his beleif bias. We tested the model experimentally. Subjects completed a psychometric questionnaire that measures three personality traits: positive reciprocity, negative reciprocity, and trust. Subsequently, they played a sequential prisoner's dilemma with random rematching and payoffs changing from round to round. From the subjects' psychometric scores and game behaviors we inferred the relationship between reciprocal preferences, belief biases, and personality. The results confirmed the hypotheses of the model.



Hartman, J. D., Jordan, A., Bayliss, D., Bakos, G. A., Bento, J., Bhatti, W., et al. (2020). HATS47b, HATS48Ab, HATS49b, and HATS72b: Four Warm Giant Planets Transiting K Dwarfs. Astron. J., 159(4), 23 pp.
Abstract: We report the discovery of four transiting giant planets around K dwarfs. The planets HATS47b, HATS48Ab, HATS49b, and HATS72b have masses of 0.369+ 0.0210.031MJ, 0.243+ 0.0300.022 MJ, 0.353+ 0.0270.038 MJ, and 0.1254. 0.0039 MJ, respectively, and radii of 1.117. 0.014 RJ, 0.800. 0.015 RJ, 0.765. 0.013 RJ, and 0.7224. 0.0032 RJ, respectively. The planets orbit close to their host stars with orbital periods of 3.9228 days, 3.1317 days, 4.1480 days, and 7.3279 days, respectively. The hosts are mainsequence K dwarfs with masses of 0.674+ 0.0120.016.M, 0.7279. 0.0066.M, 0.7133. 0.0075.M, and 0.7311. 0.0028, and with Vband magnitudes of V = 14.829. 0.010, 14.35. 0.11, 14.998. 0.040 and 12.469. 0.010. The superNeptune HATS72b (a.k.a. WASP191b and TOI 294.01) was independently identified as a transiting planet candidate by the HATSouth, WASP, and TESS surveys, and we present a combined analysis of all of the data gathered by each of these projects (and their followup programs). An exceptionally precise mass is measured for HATS72b thanks to highprecision radial velocity (RV) measurements obtained with VLT/ESPRESSO, FEROS, HARPS, and Magellan/PFS. We also incorporate TESS observations of the warm Saturnhosting systems HATS47 (a.k.a. TOI.1073.01), HATS48A, and HATS49. HATS47 was independently identified as a candidate by the TESS team, while the other two systems were not previously identified from the TESS data. The RV orbital variations are measured for these systems using Magellan/PFS. HATS48A has a resolved 5.. 4 neighbor in Gaia.DR2, which is a commonpropermotion binary star companion to HATS48A with a mass of 0.22.M and a current projected physical separation of similar to 1400 au.



Hiptmair, R., JerezHanckes, C., & UrzúaTorres, C. (2020). Optimal Operator Preconditioning For Galerkin Boundary Element Methods On 3D Screens. SIAM J. Numer. Anal., 58(1), 834–857.
Abstract: We consider firstkind weakly singular and hypersingular boundary integral operators for the Laplacian on screens in $\mathbb{R}^{3}$ and their Galerkin discretization by means of loworder piecewise polynomial boundary elements. For the resulting linear systems of equations we propose novel Calderóntype preconditioners based on (i) new boundary integral operators, which provide the exact inverses of the weakly singular and hypersingular operators on flat disks, and (ii) stable duality pairings relying on dual meshes. On screens obtained as images of the unit disk under biLipschitz transformations, this approach achieves condition numbers uniformly bounded in the meshwidth even on locally refined meshes. Comprehensive numerical tests also confirm its excellent preasymptotic performance.



Hojman, S. A., & Asenjo, F. A. (2020). A new approach to solve the onedimensional Schrodinger equation using a wavefunction potential. Phys. Lett. A, 384(36), 7 pp.
Abstract: A new approach to find exact solutions to onedimensional quantum mechanical systems is devised. The scheme is based on the introduction of a potential function for the wavefunction, and the equation it satisfies. We recover known solutions as well as to get new ones for both free and interacting particles with wavefunctions having vanishing and nonvanishing Bohm potentials. For most of the potentials, no solutions to the Schrodinger equation produce a vanishing Bohm potential. A (large but) restricted family of potentials allows the existence of particular solutions for which the Bohm potential vanishes. This family of potentials is determined, and several examples are presented. It is shown that some quantum, such as accelerated Airy wavefunctions, are due to the presence of nonvanishing Bohm potentials. New examples of this kind are found and discussed. (C) 2020 Elsevier B.V. All rights reserved.



Hojman, S. A., & Asenjo, F. A. (2020). Classical and Quantum Dispersion Relations. Phys. Scr., 95(8), 7 pp.
Abstract: It is showed that, in general, classical and quantum dispersion relations are different due to the presence of the Bohm potential. There are exact particular solutions of the quantum (wave) theory which obey the classical dispersion relation, but they differ in the general case. The dispersion relations may also coincide when additional assumptions are made, such as WKB or eikonal approximations, for instance. This general result also holds for nonquantum wave equations derived from classical counterparts, such as in ray and wave optics, for instance. Explicit examples are given for covariant scalar, vectorial and tensorial fields in flat and curved spacetimes.



Hojman, S. A., & Asenjo, F. A. (2020). Dual wavefunctions in twodimensional quantum mechanics. Phys. Lett. A, 384(13), 5 pp.
Abstract: It is shown that the Schrodinger equation for a large family of pairs of twodimensional quantum potentials possess wavefunctions for which the amplitude and the phase are interchangeable, producing two different solutions which are dual to each other. This is a property of solutions with vanishing Bohm potential. These solutions can be extended to threedimensional systems. We explicitly calculate dual solutions for physical systems, such as the repulsive harmonic oscillator and the twodimensional hydrogen atom. These dual wavefunctions are also solutions of an analogue optical system in the eikonal limit. In this case, the potential is related to the refractive index, allowing the study of this twodimensional dual wavefunction solutions with an optical (analogue) system. (C) 2020 Elsevier B.V. All rights reserved.



Hojman, S. A., & Asenjo, F. A. (2020). Phenomenological dynamics of COVID19 pandemic: Metaanalysis for adjustment parameters. Chaos, 30(10), 12 pp.
Abstract: We present a phenomenological procedure of dealing with the COVID19 (coronavirus disease 2019) data provided by government health agencies of 11 different countries. Usually, the exact or approximate solutions of susceptibleinfectedrecovered (or other) model(s) are obtained fitting the data by adjusting the timeindependent parameters that are included in those models. Instead of that, in this work, we introduce dynamical parameters whose timedependence may be phenomenologically obtained by adequately extrapolating a chosen subset of the daily provided data. This phenomenological approach works extremely well to properly adjust the number of infected (and removed) individuals in time for the countries we consider. Besides, it can handle the subepidemic events that some countries may experience. In this way, we obtain the evolution of the pandemic without using any a priori model based on differential equations.



Hojmann, S. A., & Asenjo, F. A. (2020). Quantum particles that behave as free classical particles. Phys. Rev. A, 102(5), 052211.
Abstract: The existence of nonvanishing Bohm potentials, in the MadelungBohm version of the Schrödinger equation, allows for the construction of particular solutions for states of quantum particles interacting with nontrivial external potentials that propagate as free classical particles. Such solutions are constructed with phases which satisfy the classical HamiltonJacobi for free particles and whose probability densities propagate with constant velocity, as free classical particles do.



Jenkins, J. S., Diaz, M. R., Kurtovic, N. T., Espinoza, N., Vines, J. I., Rojas, P. A. P., et al. (2020). An ultrahot Neptune in the Neptune desert. Nat. Astron., 4(12), 1148–1157.
Abstract: About 1 out of 200 Sunlike stars has a planet with an orbital period shorter than one day: an ultrashortperiod planet(1,2). All of the previously known ultrashortperiod planets are either hot Jupiters, with sizes above 10 Earth radii (Rcircle plus), or apparently rocky planets smaller than 2 Rcircle plus. Such lack of planets of intermediate size (the `hot Neptune desert') has been interpreted as the inability of lowmass planets to retain any hydrogen/ helium (H/He) envelope in the face of strong stellar irradiation. Here we report the discovery of an ultrashortperiod planet with a radius of 4.6 Rcircle plus and a mass of 29 Mcircle plus, firmly in the hot Neptune desert. Data from the Transiting Exoplanet Survey Satellite(3) revealed transits of the bright Sunlike star LTT 9779 every 0.79 days. The planet's mean density is similar to that of Neptune, and according to thermal evolution models, it has a H/Herich envelope constituting 9.0(2.9)(+2.7) % of the total mass. With an equilibrium temperature around 2,000 K, it is unclear how this `ultrahot Neptune' managed to retain such an envelope. Followup observations of the planet's atmosphere to better understand its origin and physical nature will be facilitated by the star's brightness (Vmag = 9.8).

