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1I/`Oumuamua as a Tidal Disruption Fragment From a Binary Star SystemDec 05 2017Dec 18 20171I/`Oumuamua is the first known interstellar small body, probably being only about 100~m in size. Against expectations based on comets, `Oumuamua does not show any activity and has a very elongated figure, and also exhibits undamped rotational tumbling. ... More

Hungaria Asteroid Family as the Source of Aubrite MeteoritesJun 03 2014The Hungaria asteroids are interior to the main asteroid belt, with semimajor axes between 1.8 and 2 AU, low eccentricities and inclinations of 16-35 degrees. Small asteroids in the Hungaria region are dominated by a collisional family associated with ... More

Titan-Hyperion Resonance and the Tidal Q of SaturnNov 26 2013Lainey et al. (2012), by re-analyzing long-baseline astrometry of Saturn's moons, have found that the moons' tidal evolution is much faster than previously thought, implying an order of magnitude stronger tidal dissipation within Saturn. This result is ... More

Chronology and Sources of Lunar Impact BombardmentNov 30 2011The Moon has suffered intense impact bombardment ending at 3.9 Gyr ago, and this bombardment probably affected all of the inner Solar System. Basin magnetization signatures and lunar crater size-distributions indicate that the last episode of bombardment ... More

Yarkovsky-Driven Spreading of the Eureka Family of Mars TrojansDec 04 2014Out of nine known stable Mars Trojans, seven appear to be members of an orbital grouping including the largest Trojan, Eureka. In order to test if this could be a genetic family, we simulated the long term evolution of a tight orbital cluster centered ... More

Long-Term Stability of Horseshoe OrbitsJun 08 2012Aug 24 2012Unlike Trojans, horseshoe coorbitals are not generally considered to be long-term stable (Dermott and Murray, 1981; Murray and Dermott, 1999). As the lifetime of Earth's and Venus's horseshoe coorbitals is expected to be about a Gyr, we investigated the ... More

Secular Resonance Between Iapetus and the Giant PlanetsSep 24 2018Using numerical integrations, we find that the orbital eccentricity of Saturn's moon Iapetus undergoes prominent multi-Myr oscillations. We identify the responsible resonant argument to be $\varpi-\varpi_{g5}+\Omega-\Omega_{eq}$, with the terms being ... More

Planetary Chaos and the (In)stability of Hungaria AsteroidsApr 18 2017The Hungaria asteroid group is located interior to the main asteroid belt, with semimajor axes between 1.8 and 2 AU, low eccentricities and inclinations of 16-35 degrees. Recently, it has been proposed that Hungaria asteroids are a secularly declining ... More

Tidal evolution of the Moon from a high-obliquity, high-angular-momentum EarthFeb 09 2018In the giant impact hypothesis for lunar origin, the Moon accreted from an equatorial circum-terrestrial disk; however the current lunar orbital inclination of 5 degrees requires a subsequent dynamical process that is still debated. In addition, the giant ... More

On the Dynamics and Origin of Haumea's MoonsAug 08 2013The dwarf planet Haumea has two large satellites, Namaka and Hi'iaka, which orbit at relatively large separations. Both moons have significant eccentricities and inclinations, in a pattern that is consistent with a past orbital resonance (Ragozzine and ... More

Dynamical Evidence for a Late Formation of Saturn's MoonsMar 23 2016We explore the past evolution of Saturn's moons using direct numerical integrations. We find that the past Tethys-Dione 3:2 orbital resonance predicted in standard models likely did not occur, implying that the system is less evolved than previously thought. ... More

Ruin under stochastic dependence between premium and claim arrivalsFeb 15 2016We investigate, focusing on the ruin probability, an adaptation of the Cramer-Lundberg model for the surplus process of an insurance company, in which, conditionally on their intensities, the two mixed Poisson processes governing the arrival times of ... More

First passage upwards for state dependent-killed spectrally negative Lévy processesMar 13 2018Apr 14 2018For a spectrally negative L\'evy process (snLp) $X$, killed according to a rate that is a function $\omega$ of its position, we analyse the exit probability of the one-sided upwards-passage problem. When $\omega$ is strictly positive, this problem is ... More

Ruin under stochastic dependence between premium and claim arrivalsFeb 15 2016Jun 26 2017We investigate, focusing on the ruin probability, an adaptation of the Cramer-Lundberg model for the surplus process of an insurance company, in which, conditionally on their intensities, the two mixed Poisson processes governing the arrival times of ... More

Observing a Lévy process up to a stopping timeDec 12 2018It is proved that the law of a possibly killed L\'evy process $X$, seen up to and including (resp. up to strictly before) a stopping time, determines already the law of $X$ (resp. up to a compound Poisson component and killing).

Exit problems for positive self-similar Markov processes with one-sided jumpsJul 02 2018Mar 06 2019A systematic exposition of scale functions is given for positive self-similar Markov processes (pssMp) with one-sided jumps. The scale functions express as convolution series of the usual scale functions associated with spectrally one-sided L\'evy processes ... More

Inferring Algebraic EffectsDec 09 2013Sep 11 2014We present a complete polymorphic effect inference algorithm for an ML-style language with handlers of not only exceptions, but of any other algebraic effect such as input & output, mutable references and many others. Our main aim is to offer the programmer ... More

On laws exhibiting universal ordering under stochastic restartApr 23 2019For each of (i) arbitrary stochastic reset, (ii) deterministic reset with arbitrary period, (iii) reset at arbitrary constant rate, and then in the sense of either (a) first-order stochastic dominance or (b) expectation (i.e. for each of the six possible ... More

Proper two-sided exits of a Lévy processNov 24 2015It is proved that the two-sided exits of a Levy process are proper, i.e. not a.s. equal to their one-sided counterparts, if and only if said process is not a subordinator or the negative of a subordinator. Furthermore, Levy processes are characterized, ... More

Another characterization of homogeneous Poisson processesOct 23 2016Aug 13 2017For a general renewal process $N$ (allowing delay, defect and multiple simultaneous arrivals) the independence of the first renewal epochs of the marked processes got from $N$ by Bernoulli $0$/$1$ thinning is characterized. This independence is well-known ... More

Another characterization of homogeneous Poisson processesOct 23 2016For a general renewal process $N$ (with delay and defect) the independence of the first renewal epochs of the marked processes got from $N$ by Bernoulli $0$/$1$ thinning is characterized. By way of corollary we obtain a related characterization of homogeneous ... More

A couple of remarks on the convergence of $σ$-fields on probability spacesJun 09 2016The following modes of convergence of sub-$\sigma$-fields on a given probability space have been studied in the literature: weak convergence, strong convergence, convergence with respect to the Hausdorff metric, almost-sure convergence, set-theoretic ... More

A couple of remarks on the convergence of $σ$-fields on probability spacesJun 09 2016Jun 26 2017The following modes of convergence of sub-$\sigma$-fields on a given probability space have been studied in the literature: weak convergence, strong convergence, convergence with respect to the Hausdorff metric, almost-sure convergence, set-theoretic ... More

Congruences for sporadic sequences and modular forms for non-congruence subgroupsJan 10 2019In the course of the proof of the irrationality of zeta(2) R. Apery introduced numbers b_n = \sum_{k=0}^n {n \choose k}^2{n+k \choose k}. Stienstra and Beukers showed that for the prime p > 3 Apery numbers satisfy congruence b((p-1)/2) = 4a^2-2p mod p, ... More

Excursions of a spectrally negative Lévy process from a two-point setSep 03 2018Let $a\in (0,\infty)$. For a spectrally negative L\'evy process $X$ with infinite variation paths the resolvent of the process killed on hitting the two-point set $V=\{-a,a\}$ is identified. When further $X$ has no diffusion component the Laplace transforms ... More

Non-random overshoots of Lévy processesJan 18 2013Sep 23 2013The class of Levy processes for which overshoots are almost surely constant quantities is precisely characterized.

Fluctuation theory for upwards skip-free Lévy chainsSep 20 2013May 18 2015A fluctuation theory and, in particular, a theory of scale functions is developed for upwards skip-free L\'evy chains, i.e. for right-continuous random walks embedded into continuous time as compound Poisson processes. This is done by analogy to the spectrally ... More

A note on the times of first passage for `nearly right-continuous' random walksOct 24 2013Aug 12 2014A natural extension of a right-continuous integer-valued random walk is one which can jump to the right by one or two units. First passage times above a given fixed level then admit a tractable Laplace transform (probability generating function). Explicit ... More

On the existence of a minimal generating set for $σ$-algebrasJun 03 2014Does there exist for any $\sigma$-algebra a minimal (with respect to inclusion) generating set? We formulate this problem and answer it in the very special instance of partition generated and standard measurable spaces, the general case remaining open. ... More

Exit problems for positive self-similar Markov processes with one-sided jumpsJul 02 2018A systematic exposition of scale functions is given for positive self-similar Markov processes (pssMp) with one-sided jumps. The scale functions express as convolution series of the usual scale functions associated with spectrally one-sided L\'evy processes ... More

A temporal factorization at the maximum for spectrally negative positive self-similar Markov processesMay 10 2018May 15 2018For a spectrally negative positive self-similar Markov process with an a.s. finite overall supremum we provide, in tractable detail, a kind of conditional Wiener-Hopf factorization at the maximum of the absorption time at zero, the conditioning being ... More

Independence times for iid sequences, random walks and Lévy processesApr 20 2017Sep 28 2018For a sequence in discrete time having stationary independent values (respectively, random walk) $X$, those random times $R$ of $X$ are characterized set-theoretically, for which the strict post-$R$ sequence (respectively, the process of the increments ... More

An Effect System for Algebraic Effects and HandlersJun 26 2013Dec 09 2014We present an effect system for core Eff, a simplified variant of Eff, which is an ML-style programming language with first-class algebraic effects and handlers. We define an expressive effect system and prove safety of operational semantics with respect ... More

Programming with Algebraic Effects and HandlersMar 07 2012Eff is a programming language based on the algebraic approach to computational effects, in which effects are viewed as algebraic operations and effect handlers as homomorphisms from free algebras. Eff supports first-class effects and handlers through ... More

On a special case of Watkins' conjectureNov 17 2016Watkins' conjecture asserts that for a rational elliptic curve $E$ the degree of the modular parametrization is divisible by $2^r$, where $r$ is the rank of $E$. In this paper we prove that if the modular degree is odd then $E$ has rank $0$. Moreover, ... More

On the informational structure in optimal dynamic stochastic controlMar 09 2015Sep 20 2016We formulate a very general framework for optimal dynamic stochastic control problems which allows for a control-dependent informational structure. The issue of informational consistency is investigated. Bellman's principle is formulated and proved. In ... More

Supersingular zeros of divisor polynomials of elliptic curves of prime conductorNov 17 2016For a prime number $p$ we study the zeros modulo $p$ of divisor polynomials of rational elliptic curves $E$ of conductor $p$. Ono made the observation that these zeros of are often $j$-invariants of supersingular elliptic curves over $\overline{\mathbb{F}_p}$. ... More

No value restriction is needed for algebraic effects and handlersMay 23 2016We present a straightforward, sound Hindley-Milner polymorphic type system for algebraic effects and handlers in a call-by-value calculus, which allows type variable generalisation of arbitrary computations, not just values. This result is surprising. ... More

SW# - GPU enabled exact alignments on genome scaleApr 22 2013Sequence alignment is one of the oldest and the most famous problems in bioinformatics. Even after 45 years, for one reason or another, this problem is still actual; current solutions are trade-offs between execution time, memory consumption and accuracy. ... More

On the informational structure in optimal dynamic stochastic controlMar 09 2015May 15 2018We formulate a very general framework for optimal dynamic stochastic control problems which allows for a control-dependent informational structure. The issue of informational consistency is investigated. Bellman's principle is formulated and proved. In ... More

First passage problems for upwards skip-free random walks via the $Φ,W,Z$ paradigmAug 21 2017Apr 14 2018We develop the theory of the $W$ and $Z$ scale functions for right-continuous (upwards skip-free) discrete-time discrete-space random walks, along the lines of the analogue theory for spectrally negative L\'evy processes. Notably, we introduce for the ... More

Diophantine m-tuples in finite fields and modular formsSep 29 2016For a prime p, a Diophantine m-tuple in $\mathbb{F}_p$ is a set of m nonzero elements of $\mathbb{F}_p$ with the property that the product of any two of its distinct elements is one less than a square. In this paper, we present formulas for the number ... More

Copulas for maxmin systemsDec 30 2015Under a mild condition we give closed-form expressions for copulas of systems that consist of maxima and of minima of subvectors of a given random vector $X$ with continuous marginals. Said expressions appear explicit in the copula of $X$ and the mentioned ... More

The origin of the Moon within a terrestrial synestiaFeb 28 2018The giant impact hypothesis remains the leading theory for lunar origin. However, current models struggle to explain the Moon's composition and isotopic similarity with Earth. Here we present a new lunar origin model. High-energy, high-angular momentum ... More

Modular forms, de Rham cohomology and congruencesJan 24 2013Apr 22 2013In this paper we show that Atkin and Swinnerton-Dyer type of congruences hold for weakly modular forms (modular forms that are permitted to have poles at cusps). Unlike the case of original congruences for cusp forms, these congruences are nontrivial ... More

Handling Algebraic EffectsDec 05 2013Dec 16 2013Algebraic effects are computational effects that can be represented by an equational theory whose operations produce the effects at hand. The free model of this theory induces the expected computational monad for the corresponding effect. Algebraic effects ... More

Constraints on the Orbital Evolution of TritonMay 11 2005We present simulations of Triton's post-capture orbit that confirm the importance of Kozai-type oscillations in its orbital elements. In the context of the tidal orbital evolution model, these variations require average pericenter distances much higher ... More

Generating Entangled Spin States for Quantum Metrology by Single-Photon DetectionAug 28 2013We propose and analyze a probabilistic but heralded scheme to generate pure, entangled, non-Gaussian states of collective spin in large atomic ensembles by means of single-photon detection. One photon announces the preparation of a Dicke state, while ... More

Disentangling sources of influence in online social networksNov 26 2018Nov 27 2018Information propagation in online social networks is facilitated by two types of influence - endogenous (peer) influence that is dependent on the network structure and current state of each user and exogenous (external) which is independent of these. ... More

Monochromatic paths in random tournamentsMar 30 2017Dec 09 2017We prove that, with high probability, any $2$-edge-colouring of a random tournament on $n$ vertices contains a monochromatic path of length $\Omega(n / \sqrt{\log n})$. This resolves a conjecture of Ben-Eliezer, Krivelevich and Sudakov and implies a nearly ... More

Three colour bipartite Ramsey number of cycles and pathsMar 09 2018The $k$-colour bipartite Ramsey number of a bipartite graph $H$ is the least integer $n$ for which every $k$-edge-coloured complete bipartite graph $K_{n,n}$ contains a monochromatic copy of $H$. The study of bipartite Ramsey numbers was initiated, over ... More

Disentangling sources of influence in online social networksNov 26 2018Mar 27 2019Information propagation in online social networks is facilitated by two types of influence - endogenous (peer) influence that acts between users of the social network and exogenous (external) that corresponds to various external mediators such as online ... More

Graph-Based Controller Synthesis for Safety-Constrained, Resilient SystemsAug 13 2018Resilience to damage, component degradation, and adversarial action is a critical consideration in design of autonomous systems. In addition to designing strategies that seek to prevent such negative events, it is vital that an autonomous system remains ... More

Simulating the Phases of the Moon Shortly After Its FormationMar 10 2015The leading theory for the origin of the Moon is the giant impact hypothesis, in which the Moon was formed out of the debris left over from the collision of a Mars-sized body with the Earth. Soon after its formation, the orbit of the Moon may have been ... More

Modular parametrizations of certain elliptic curvesDec 26 2012Kaneko and Sakai recently observed that certain elliptic curves whose associated newforms (by the modularity theorem) are given by the eta-quotients can be characterized by a particular differential equation involving modular forms and Ramanujan-Serre ... More

Rigidity of the Minimal Grope GroupAug 04 2006We give a systematic definition of the fundamental groups of gropes, which we call grope groups. We show that there exists a nontrivial homomorphism from the minimal grope group M to another grope group G only if G is the free product of M with another ... More

Rational Diophantine sextuples containing two regular quadruples and one regular quintupleMar 31 2019A set of $m$ distinct nonzero rationals $\{a_1,a_2,\ldots,a_m\}$ such that $a_ia_j+1$ is a perfect square for all $1\leq i<j\leq m$, is called a rational Diophantine $m$-tuple. It is proved recently that there are infinitely many rational Diophantine ... More

Multiple perturbations of a singular eigenvalue problemFeb 22 2016We study the perturbation by a critical term and a $(p-1)$-superlinear subcritical nonlinearity of a quasilinear elliptic equation containing a singular potential. By means of variational arguments and a version of the concentration-compactness principle ... More

Markov chain approximations to scale functions of Lévy processesOct 07 2013Apr 20 2015We introduce a general algorithm for the computation of the scale functions of a spectrally negative L\'evy process $X$, based on a natural weak approximation of $X$ via upwards skip-free continuous-time Markov chains with stationary independent increments. ... More

Covering random graphs by monochromatic trees and Helly-type results for hypergraphsFeb 13 2019How many monochromatic paths, cycles or general trees does one need to cover all vertices of a given $r$-edge-coloured graph $G$? These problems were introduced in the 1960's and were intensively studied by various researchers over the last 50 years. ... More

A short proof of the Twelve points theoremAug 08 2008We present a short elementary proof of the following Twelve Points Theorem: Let M be a convex polygon with vertices at the lattice points, containing a single lattice point in its interior. Denote by m (resp. m*) the number of lattice points in the boundary ... More

On structure sets of manifold pairsAug 10 2009In this paper we systematically describe relations between various structure sets which arise naturally for pairs of compact topological manifolds with boundary. Our consideration is based on a deep analogy between the case of a compact manifold with ... More

Markov chain approximations for transition densities of Lévy processesNov 02 2012Jun 26 2013We consider the convergence of a continuous-time Markov chain approximation X^h, h>0, to an R^d-valued Levy process X. The state space of X^h is an equidistant lattice and its Q-matrix is chosen to approximate the generator of X. In dimension one (d=1), ... More

The structure of non-linear martingale optimal transport problemsMar 15 2019We explore the structure of solutions to a family of non-linear martingale optimal transport (MOT) problems that involve conditional expectations in the objective functional. En route general results concerning optimization over (martingale) measures ... More

Inelastic photon scattering via the intracavity Rydberg blockadeApr 21 2016Electromagnetically induced transparency (EIT) in a ladder system involving a Rydberg level is known to yield giant optical nonlinearities for the probe field, even in the few-photon regime. This enhancement is due to the strong dipole-dipole interactions ... More

Covering random graphs by monochromatic trees and Helly-type results for hypergraphsFeb 13 2019Feb 19 2019How many monochromatic paths, cycles or general trees does one need to cover all vertices of a given $r$-edge-coloured graph $G$? These problems were introduced in the 1960's and were intensively studied by various researchers over the last 50 years. ... More

An improved bound for disjoint directed cyclesJan 23 2017Apr 24 2018We show that every directed graph with minimum out-degree at least $18k$ contains at least $k$ vertex disjoint cycles. This is an improvement over the result of Alon who showed this result for digraphs of minimum out-degree at least $64k$. The main benefit ... More

Modular forms, hypergeometric functions and congruencesJan 15 2013Using the theory of Stienstra and Beukers, we prove various elementary congruences for the numbers \sum \binom{2i_1}{i_1}^2\binom{2i_2}{i_2}^2...\binom{2i_k}{i_k}^2, where k,n \in N, and the summation is over the integers i_1, i_2, ...i_k >= 0 such that ... More

On Kahn's basis conjectureOct 17 2018In 1991, Kahn made the following conjecture. For any $n$-dimensional vector space $V$ and any $n\times n$ array of $n^2$ bases of $V$, it is possible to choose a representative vector from each of these bases in such a way that the representatives from ... More

Partition problems in high dimensional boxesMay 29 2018Jun 30 2018Alon, Bohman, Holzman and Kleitman proved that any partition of a $d$-dimensional discrete box into proper sub-boxes must consist of at least $2^d$ sub-boxes. Recently, Leader, Mili\'{c}evi\'{c} and Tan considered the question of how many odd-sized proper ... More

Coupled channel analysis of the rho meson decay in lattice QCDMay 27 2011Apr 18 2014We employ a variational basis with a number of $\bar{q}q$ and $\pi\pi$ lattice interpolating fields with quantum numbers of the $\rho$ resonance to extract the discrete energy spectrum in a finite volume. In the elastic region, this spectrum is related ... More

Coarse classification of abelian groups and amenable shift-homogeneous metric spacesDec 13 2014In this paper we classify countable locally finite-by-abelian groups up to coarse isomorphism. This classification is derived from a coarse classification of amenable shift-homogeneous metric spaces.

Double phase problems with variable growthOct 18 2018We consider a class of double phase variational integrals driven by nonhomogeneous potentials. We study the associated Euler equation and we highlight the existence of two different Rayleigh quotients. One of them is in relationship with the existence ... More

On the Expressive Power of User-Defined Effects: Effect Handlers, Monadic Reflection, Delimited ControlOct 28 2016We compare the expressive power of three programming abstractions for user-defined computational effects: Bauer and Pretnar's effect handlers, Filinski's monadic reflection, and delimited control. This comparison allows a precise discussion about the ... More

On the combinatorics of faces of trees and anodyne extensions of dendroidal setsJan 28 2018May 17 2018We discuss the combinatorics of faces of trees in the context of dendroidal sets and develop a systematic treatment of dendroidal anodyne extensions. As the main example and our motivation, we prove the pushout-product property for the stable model structure ... More

On the existence of a minimal generating set for $σ$-algebrasJun 03 2014May 16 2018Does there exist for any $\sigma$-algebra a minimal (with respect to inclusion) generating set? We formulate this problem and answer it in the very special instance of partition generated and standard measurable spaces, the general case remaining open. ... More

X-ray diffraction and computer simulation studies of the structure of liquid aliphatic aldehydes: from propanal to nonanalNov 26 2018Synchrotron X-ray diffraction experiments and molecular dynamics simulations have been performed on simple aliphatic aldehydes, from propanal to nonanal. The performance of the OPLS all-atom interaction potential model for aldehydes has been assessed ... More

Minimum saturated families of setsJan 16 2018Apr 24 2018We call a family $\mathcal{F}$ of subsets of $[n]$ $s$-saturated if it contains no $s$ pairwise disjoint sets, and moreover no set can be added to $\mathcal{F}$ while preserving this property (here $[n] = \{1,\ldots,n\}$). More than 40 years ago, Erd\H{o}s ... More

Monochromatic trees in random tournamentsSep 19 2018We prove that, with high probability, in every $2$-edge-colouring of the random tournament on $n$ vertices there is a monochromatic copy of every oriented tree of order $O (n / \sqrt{\log n})$. This generalises a result of the first, third and forth authors ... More

Collective state measurement of mesoscopic ensembles with single-atom resolutionMar 14 2012Sep 28 2012For mesoscopic ensembles containing 100 or more atoms we measure the total atom number and the number of atoms in a specific hyperfine state with single-atom resolution. The measurement detects the atom-induced shift of the resonance frequency of an optical ... More

Arithmetic of (independent) sigma-fields on probability spacesSep 14 2018This note gathers what is known about, and provides some new results concerning the operations of intersection, of "generated $\sigma$-field", and of "complementation" for (independent) complete $\sigma$-fields on probability spaces.

On the Alexandroff-Borsuk problemMar 03 2017We investigate the classical Alexandroff-Borsuk problem in the category of non-triangulable manifolds: Given an $n$-dimensional compact non-triangulable manifold $M^n$ and $\varepsilon > 0$, does there exist an $\varepsilon$-map of $M^n$ onto an $n$-dimensional ... More

Characterizing compact Clifford semigroups that embed into convolution and functor-semigroupsNov 06 2008Aug 02 2011We study algebraic and topological properties of the convolution semigroups of probability measures on a topological groups and show that a compact Clifford topological semigroup $S$ embeds into the convolution semigroup $P(G)$ over some topological group ... More

Double hypergeometric Lévy processes and self-similarityApr 12 2019Motivated by a recent paper of Budd, where a new family of positive self-similar Markov processes associated to stable processes appears, we introduce a new family of L\'evy processes, called the double hypergeometric class, whose Wiener-Hopf factorisation ... More

Student's opinions about System for automatic assessment of programming tasks Projekt TomoFeb 17 2017In a previous paper a web service called Projekt Tomo intended to ease the process of learning programming for teachers and students has been described. Since the service received a very warm welcome from teachers and students alike we decided to collect ... More

Diophantine m-tuples in finite fields and modular formsSep 29 2016Jan 31 2018For a prime p, a Diophantine m-tuple in $\mathbb{F}_p$ is a set of m nonzero elements of $\mathbb{F}_p$ with the property that the product of any two of its distinct elements is one less than a square. In this paper, we present formulas for the number ... More

Homology of dendroidal setsSep 02 2015We define for every dendroidal set X a chain complex and show that this assignment determines a left Quillen functor. Then we define the homology groups $H_n(X)$ as the homology groups of this chain complex. This generalizes the homology of simplicial ... More

Edgeless and Purely Gate-Defined Nanostructures in InAs Quantum WellsSep 07 2018Nanostructures in InAs quantum wells have so far remained outside of the scope of traditional microfabrication techniques based on etching. This is due to parasitic parallel conduction arising from charge carrier accumulation at the physical edges of ... More

The Hall effect in the organic conductor TTF-TCNQ: Choice of geometry for accurate measurements of highly anisotropic systemJan 25 2011Jan 24 2012We have measured the Hall effect on recently synthesized single crystals of quasi-one-dimensional organic conductor TTF-TCNQ, a well known charge transfer complex that has two kinds of conductive stacks: the donor (TTF) and the acceptor (TCNQ) chains. ... More

News Cohesiveness: an Indicator of Systemic Risk in Financial MarketsFeb 14 2014Motivated by recent financial crises significant research efforts have been put into studying contagion effects and herding behaviour in financial markets. Much less has been said about influence of financial news on financial markets. We propose a novel ... More

Lateral p-n Junction in an Inverted InAs/GaSb Double Quantum WellMar 24 2017May 21 2017We present transport measurements on a lateral p-n junction in an inverted InAs/GaSb double quantum well at zero and nonzero perpendicular magnetic fields. At a zero magnetic field, the junction exhibits diodelike behavior in accordance with the presence ... More

Design and Implementation of the Andromeda Proof AssistantFeb 17 2018Andromeda is an LCF-style proof assistant where the user builds derivable judgments by writing code in a meta-level programming language AML. The only trusted component of Andromeda is a minimalist nucleus (an implementation of the inference rules of ... More

Modeling peer and external influence in online social networksOct 26 2016Opinion polls mediated through a social network can give us, in addition to usual demographics data like age, gender and geographic location, a friendship structure between voters and the temporal dynamics of their activity during the voting process. ... More

Nearly-linear monotone paths in edge-ordered graphsSep 05 2018May 02 2019How long a monotone path can one always find in any edge-ordering of the complete graph $K_n$? This appealing question was first asked by Chv\'atal and Koml\'os in 1971, and has since attracted the attention of many researchers, inspiring a variety of ... More

Nearly-linear monotone paths in edge-ordered graphsSep 05 2018How long a monotone path can one always find in any edge-ordering of the complete graph $K_n$? This appealing question was first asked by Chv\'atal and Koml\'os in 1971, and has since attracted the attention of many researchers, inspiring a variety of ... More

More on Diophantine sextuplesSep 22 2016A rational Diophantine m-tuple is a set of m nonzero rationals such that the product of any two of them increased by 1 is a perfect square. The first rational Diophantine quadruple was found by Diophantus, while Euler proved that there are infinitely ... More

Fluorescence-lifetime-limited trapping of Rydberg helium atoms on a chipApr 16 2019Metastable (1s)(2s) $^3{\rm S}_1$ helium atoms produced in a supersonic beam were excited to Rydberg-Stark states (with $n$ in the $27-30$ range) in a cryogenic environment and subsequently decelerated by, and trapped above, a surface-electrode decelerator. ... More

Rydberg states of helium in electric and magnetic fields of arbitrary relative orientationJan 06 2017A spectroscopic study of Rydberg states of helium ($n$ = 30 and 45) in magnetic, electric and combined magnetic and electric fields with arbitrary relative orientations of the field vectors is presented. The emphasis is on two special cases where (i) ... More

Phase Slips and Parity Jumps in Quantum Oscillations of Inverted InAs/GaSb Quantum WellsSep 21 2018We present magnetotransport measurements of a strongly hybridized inverted InAs/GaSb double quantum well. We find that the spin-orbit interaction leads to an appreciable spin-splitting of hole-like states, which form distinct Landau levels in a perpendicular ... More

Satisfiability Thresholds for Regular Occupation ProblemsNov 02 2018Apr 27 2019In the last two decades the study of random instances of constraint satisfaction problems (CSPs) has flourished across several disciplines, including computer science, mathematics and physics. The diversity of the developed methods, on the rigorous and ... More