Results for "Benjamin V. Rackham"

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The Transit Light Source Effect II: The Impact of Stellar Heterogeneity on Transmission Spectra of Planets Orbiting Broadly Sun-like StarsDec 14 2018Transmission spectra probe exoplanetary atmospheres, but they can also be strongly affected by heterogeneities in host star photospheres through the transit light source effect. Here we build upon our recent study of the effects of unocculted spots and ... More
The Transit Light Source Effect: False Spectral Features and Incorrect Densities for M-dwarf Transiting PlanetsNov 15 2017Jan 24 2018Transmission spectra are differential measurements that utilize stellar illumination to probe transiting exoplanet atmospheres. Any spectral difference between the illuminating light source and the disk-integrated stellar spectrum due to starspots and ... More
Retrieval of planetary and stellar properties in transmission spectroscopy with AuraAug 29 2018Transmission spectroscopy provides a powerful probe of the atmospheric properties of transiting exoplanets. To date, studies of exoplanets in transit have focused on inferring their atmospheric properties such as chemical compositions, cloud/haze properties, ... More
The Near-Infrared Transmission Spectra of TRAPPIST-1 Planets b, c, d, e, f, and g and Stellar Contamination in Multi-Epoch Transit SpectraFeb 06 2018Aug 31 2018The seven approximately Earth-sized transiting planets in the \object{TRAPPIST-1} system provide a unique opportunity to explore habitable zone and non-habitable zone small planets within the same system. Its habitable zone exoplanets -- due to their ... More
Back to "Normal" for the Disintegrating Planet Candidate KIC 12557548 bOct 23 2018Nov 11 2018KIC 12557548 b is first of a growing class of intriguing disintegrating planet candidates, which lose mass in the form of a metal rich vapor that condenses into dust particles. Here, we follow up two perplexing observations of the system: 1) the transits ... More
ACCESS I: An Optical Transmission Spectrum of GJ 1214b Reveals a Heterogeneous Stellar PhotosphereDec 01 2016GJ 1214b is the most studied sub-Neptune exoplanet to date. Recent measurements have shown its near-infrared transmission spectrum to be flat, pointing to a high-altitude opacity source in the exoplanet's atmosphere, either equilibrium condensate clouds ... More
ACCESS: Ground-based Optical Transmission Spectroscopy of the Hot Jupiter WASP-4bDec 18 2018We present an optical transmission spectrum of the atmosphere of WASP-4b obtained through observations of four transits with Magellan/IMACS. Using a Bayesian approach to atmospheric retrieval, we find no evidence for scattering or absorption features ... More
ACCESS: A featureless optical transmission spectrum for WASP-19b from Magellan/IMACSJul 27 2018Oct 02 2018The short period ($0.94$-day) transiting exoplanet WASP-19b is an exceptional target for transmission spectroscopy studies, due to its relatively large atmospheric scale-height ($\sim 500$ km) and equilibrium temperature ($\sim 2100$ K). Here we report ... More
Detecting Earth-like Biosignatures on Rocky Exoplanets around Nearby Stars with Ground-based Extremely Large TelescopesMar 22 2019As we begin to discover rocky planets in the habitable zone of nearby stars with missions like TESS and CHEOPS, we will need quick advancements on instrumentation and observational techniques that will enable us to answer key science questions, such as ... More
Understanding Stellar Contamination in Exoplanet Transmission Spectra as an Essential Step in Small Planet CharacterizationMar 23 2018Transmission spectroscopy during planetary transits is expected to be a major source of information on the atmospheres of small (approximately Earth-sized) exoplanets in the next two decades. This technique, however, is intrinsically affected by stellar ... More
Constraining Stellar Photospheres as an Essential Step for Transmission Spectroscopy of Small ExoplanetsMar 14 2019Transmission spectra probe the atmospheres of transiting exoplanets, but these observations are also subject to signals introduced by magnetic active regions on host stars. Here we outline scientific opportunities in the next decade for providing useful ... More
A Statistical Comparative Planetology Approach to Maximize the Scientific Return of Future Exoplanet Characterization EffortsMar 12 2019Provided that sufficient resources are deployed, we can look forward to an extraordinary future in which we will characterize potentially habitable planets. Until now, we have had to base interpretations of observations on habitability hypotheses that ... More
On Permutiples Having a Fixed Set of DigitsNov 06 2015A permutiple is the product of a digit preserving multiplication, that is, a number which is an integer multiple of some permutation of its digits. Certain permutiple problems, particularly transposable, cyclic, and, more recently, palintiple numbers, ... More
Digit Preserving Multiplication in Continued Fraction RepresentationsFeb 15 2017A permutiple is a number which is an integer multiple of some permutation of its digits. A well-known example is 9801 since it is an integer multiple of its reversal, 1089. In this paper, we consider the permutiple problem in an entirely different setting: ... More
Some Thoughts on Determining Symmetric PalintiplesOct 09 2014Mar 28 2015A palintiple is a natural number which is an integer multiple of its digit reversal. A previous paper partitions all palintiples into three distinct classes according to patterns in the carries and then determines all palintiples belonging to the shifted-symmetric ... More
Derived Palintiple Families and Their PalinomialsNov 30 2014Mar 28 2015We consider several families of palintiples (also known as reverse multiples) whose carries themselves are digits of lower-base palintiples and give some methods for constructing them from fundamental palintiple types. We also continue the study of palinomials ... More
On Permutiples Having a Fixed Set of DigitsNov 06 2015Jan 27 2017A permutiple is the product of a digit preserving multiplication, that is, a number which is an integer multiple of some permutation of its digits. Certain permutiple problems, particularly transposable, cyclic, and, more recently, palintiple numbers, ... More
Derived Palintiple Families and Their PalinomialsNov 30 2014Feb 17 2017We consider several families of palintiples (also known as reverse multiples) whose carries themselves are digits of lower-base palintiples and give some methods for constructing them from fundamental palintiple types. We also continue the study of palinomials ... More
Erdos-Szekeres tableauxJul 02 2014We explore a question related to the celebrated Erd\H{o}s-Szekeres Theorem and develop a geometric approach to answer it. Our main object of study is the Erd\H{o}s-Szekeres tableau, or EST, of a number sequence. An EST is the sequence of integral points ... More
ABJM flux-tube and scattering amplitudesNov 24 2018There is a number of indications that scattering amplitudes in the Aharony-Bergman-Jafferis-Maldacena theory might have a dual description in terms of a holonomy of a supergauge connection on a null polygonal contour in a way analogous to the four-dimensional ... More
The stochastic thin-film equation: existence of nonnegative martingale solutionsApr 18 2019We consider the stochastic thin-film equation with colored Gaussian Stratonovich noise and establish the existence of nonnegative weak (martingale) solutions. The construction is based on a Trotter-Kato-type decomposition into a deterministic and a stochastic ... More
Helium in the eroding atmosphere of an exoplanetMay 03 2018Helium is the second-most abundant element in the Universe after hydrogen and is one of the main constituents of gas-giant planets in our Solar System. Early theoretical models predicted helium to be among the most readily detectable species in the atmospheres ... More
The Near-Infrared Transmission Spectra of TRAPPIST-1 Planets b, c, d, e, f, and g and Stellar Contamination in Multi-Epoch Transit SpectraFeb 06 2018The seven approximately Earth-sized transiting planets in the TRAPPIST-1 system provide a unique opportunity to explore habitable zone and non-habitable zone small planets within the same system. Its habitable zone exoplanets -- due to their favorable ... More
Pro-aperiodic monoids via saturated modelsSep 25 2016Aug 28 2017We apply Stone duality and model theory to study the structure theory of free pro-aperiodic monoids. Stone duality implies that elements of the free pro-aperiodic monoid may be viewed as elementary equivalence classes of pseudofinite words. Model theory ... More
Alfven Wave Reflection and Turbulent Heating in the Solar Wind from 1 Solar Radius to 1 AU: an Analytical TreatmentNov 05 2009We study the propagation, reflection, and turbulent dissipation of Alfven waves in coronal holes and the solar wind. We start with the Heinemann-Olbert equations, which describe non-compressive magnetohydrodynamic fluctuations in an inhomogeneous medium ... More
Epidemiological consequences of an ineffective Bordetella pertussis vaccineFeb 28 2014The recent increase in Bordetella pertussis incidence (whooping cough) presents a challenge to global health. Recent studies have called into question the effectiveness of acellular B. pertussis vaccination in reducing transmission. Here we examine the ... More
Dynamic polarizabilities and magic wavelengths for dysprosiumNov 22 2010We theoretically study dynamic scalar polarizabilities of the ground and select long-lived excited states of dysprosium, a highly magnetic atom recently laser cooled and trapped. We demonstrate that there are a set of magic wavelengths of the unpoarized ... More
Resolving the Solar Neutrino Problem with KamLANDNov 20 2000Feb 26 2001We study how well KamLAND, the first terrestrial neutrino experiment capable of addressing the solar neutrino problem, will perform in ascertaining whether or not the large mixing angle MSW solution (with $10^{-5}<\Delta m_{21}^2< 10^{-4} eV^2$ and oscillation ... More
Nonparametric Covariate Adjustment for Receiver Operating Characteristic CurvesMay 04 2009The accuracy of a diagnostic test is typically characterised using the receiver operating characteristic (ROC) curve. Summarising indexes such as the area under the ROC curve (AUC) are used to compare different tests as well as to measure the difference ... More
The Spectra of Lamplighter Groups and Cayley MachinesDec 20 2004Sep 09 2005We calculate the spectra and spectral measures associated to random walks on restricted wreath products of finite groups with the infinite cyclic group, by calculating the Kesten-von Neumann-Serre spectral measures for the random walks on Schreier graphs ... More
On the rational subset problem for groupsFeb 21 2006We use language theory to study the rational subset problem for groups and monoids. We show that the decidability of this problem is preserved under graph of groups constructions with finite edge groups. In particular, it passes through free products ... More
Merge decompositions, two-sided Krohn-Rhodes, and aperiodic pointlikesAug 27 2017This paper provides short proofs of two fundamental theorems of finite semigroup theory whose previous proofs were significantly longer, namely the two-sided Krohn-Rhodes decomposition theorem and Henckell's aperiodic pointlike theorem, using a new algebraic ... More
Connecting direct and indirect detection with a dark spike in the cosmic-ray electron spectrumMar 17 2019Multiple space-borne cosmic ray detectors have detected line-like features in the electron and positron spectra. Most recently, the DAMPE collaboration reported the existence of such a feature at 1.4 TeV, sparking interest in a potential dark matter origin. ... More
Torus Principal Component Analysis with an Application to RNA StructuresNov 16 2015There are several cutting edge applications needing PCA methods for data on tori and we propose a novel torus-PCA method with important properties that can be generally applied. There are two existing general methods: tangent space PCA and geodesic PCA. ... More
Gaussianisation for fast and accurate inference from cosmological dataSep 30 2015Jun 13 2016We present a method to transform multivariate unimodal non-Gaussian posterior probability densities into approximately Gaussian ones via non-linear mappings, such as Box--Cox transformations and generalisations thereof. This permits an analytical reconstruction ... More
Heating of Milky Way disc Stars by Dark Matter Fluctuations in Cold Dark Matter and Fuzzy Dark Matter ParadigmsSep 13 2018Feb 21 2019Although highly successful on cosmological scales, Cold Dark Matter (CDM) models predict unobserved over-dense `cusps' in dwarf galaxies and overestimate their formation rate. We consider an ultra-light axion-like scalar boson which promises to reduce ... More
Numerical hydrodynamic simulations based on semi-analytic galaxy merger trees: method and Milky-Way like galaxiesOct 19 2012We present a new approach to study galaxy evolution in a cosmological context. We combine cosmological merger trees and semi-analytic models of galaxy formation to provide the initial conditions for multi-merger hydrodynamic simulations. In this way we ... More
Remarks on the Rényi Entropy of a sum of IID random variablesApr 17 2019In this note we study a conjecture of Madiman and Wang which predicted that the generalized Gaussian distribution minimizes the R\'{e}nyi entropy of the sum of independent random variables. Through a variational analysis, we show that the generalized ... More
The Origins Space Telescope: Towards An Understanding of Temperate Planetary AtmospheresMar 21 2018The Origins Space Telescope (OST) is one of four mission concepts currently being studied by NASA in preparation for the Astrophysics 2020 Decadal Survey. With active cooling (~4 K), OST will be sensitive in mid- to far-IR wavelengths, using imaging and ... More
Chandra X-ray Imaging Spectroscopy of the Young Supernova Remnant Kesteven 75Sep 18 2002We present a spatially resolved spectroscopic analysis of the young Galactic supernova remnant Kes 75 (SNR G29.7-0.3) using the Chandra X-ray Observatory. Kes 75 is one of an increasing number of examples of a shell-type remnant with a central pulsar ... More
The Dust Content of Galaxy ClustersNov 07 2007We report on the detection of reddening toward z ~ 0.2 galaxy clusters. This is measured by correlating the Sloan Digital Sky Survey cluster and quasar catalogs and by comparing the photometric and spectroscopic properties of quasars behind the clusters ... More
Knot Diagrams of Treewidth TwoApr 05 2019In this paper, we study knot diagrams for which the underlying graph has treewidth two. We give a linear time algorithm for the following problem: given a knot diagram of treewidth two, does it represent the unknot? We also show that for a link diagram ... More
A tight colored Tverberg theorem for maps to manifoldsJul 10 2011We prove that any continuous map of an N-dimensional simplex Delta_N with colored vertices to a d-dimensional manifold M must map r points from disjoint rainbow faces of Delta_N to the same point in M: For this we have to assume that N \geq (r-1)(d+1), ... More
Transits of Inclined Exomoons - Hide and Seek and an Application to Kepler-1625Jan 18 2019A Neptune-sized exomoon candidate was recently announced by Teachey & Kipping (2018), orbiting a 287-day gas giant in the Kepler-1625 system. However, the system is poorly characterized and needs more observations to be confirmed, with the next potential ... More
Transits of Inclined Exomoons - Hide and Seek and an Application to Kepler-1625Jan 18 2019Apr 02 2019A Neptune-sized exomoon candidate was recently announced by Teachey & Kipping, orbiting a 287 day gas giant in the Kepler-1625 system. However, the system is poorly characterized and needs more observations to be confirmed, with the next potential transit ... More
Semileptonic B and Lambda_b Decays and Local Duality in QCDNov 03 1995Nov 19 1995The inclusive and exclusive semileptonic decay distributions for b -> c decay are computed in the Shifman-Voloshin limit. The inclusive decay distributions (computed using an operator product expansion) depend on quark masses, and the exclusive decay ... More
The interaction of long and short waves in dispersive mediaApr 15 2016The KdV equation models the propagation of long waves in dispersive media, while the NLS equation models the dynamics of narrow-bandwidth wave packets consisting of short dispersive waves. A system that couples the two equations to model the interaction ... More
The Roots of Bias on UberMar 22 2018In the last decade, there has been a growth in, what we call, digitally mediated workplaces. A digitally mediated workplace is one where interactions between stakeholders are primarily managed by proprietary, algorithmically managed digital platform. ... More
Optimal bounds for the colored Tverberg problemOct 26 2009Nov 17 2014We prove a "Tverberg type" multiple intersection theorem. It strengthens the prime case of the original Tverberg theorem from 1966, as well as the topological Tverberg theorem of Barany et al. (1980), by adding color constraints. It also provides an improved ... More
Signatures of Chaos in Time Series Generated by Many-Spin Systems at High TemperaturesMay 23 2011Sep 18 2014Extracting reliable indicators of chaos from a single experimental time series is a challenging task, in particular, for systems with many degrees of freedom. The techniques available for this purpose often require unachievably long time series. In this ... More
Knot Diagrams of Treewidth TwoApr 05 2019Apr 08 2019In this paper, we study knot diagrams for which the underlying graph has treewidth two. We give a linear time algorithm for the following problem: given a knot diagram of treewidth two, does it represent the unknot? We also show that for a link diagram ... More
New Nuclear Magnetic Moment of $^{209}$Bi - Resolving the Bismuth Hyperfine PuzzleMar 07 2018A recent measurement of the hyperfine splitting in the ground state of Li-like $^{209}$Bi$^{80+}$ has established a "hyperfine puzzle" -- the experimental result exhibits a 7$\sigma$ deviation from the theoretical prediction [J. Ullmann et al., Nat. Commun. ... More
Model Independent Expansion History from Supernovae: Deviation from $Λ$CDM?Dec 10 2018We examine the Pantheon supernovae distance data compilation in a model independent analysis to test the validity of cosmic history reconstructions beyond the concordance $\Lambda$CDM cosmology. Strong deviations are allowed by the data at $z\gtrsim1$ ... More
Generating topological order from a 2D cluster state using a duality mappingMay 11 2011In this paper we prove, extend and review possible mappings between the two-dimensional Cluster state, Wen's model, the two-dimensional Ising chain and Kitaev's toric code model. We introduce a two-dimensional duality transformation to map the two-dimensional ... More
Model Independent Expansion History from Supernovae: Cosmology versus SystematicsDec 10 2018Mar 03 2019We examine the Pantheon supernovae distance data compilation in a model independent analysis to test the validity of cosmic history reconstructions beyond the concordance $\Lambda$CDM cosmology. Strong deviations are allowed by the data at $z\gtrsim1$ ... More
From Discs to Bulges: effect of mergers on the morphology of galaxiesJul 16 2015We study the effect of mergers on the morphology of galaxies by means of the simulated merger tree approach first proposed by Moster et al. This method combines N-body cosmological simulations and semi-analytic techniques to extract realistic initial ... More
Graphene on a hydrophobic substrate: Doping reduction and hysteresis suppression under ambient conditionsOct 14 2009The intrinsic doping level of graphene prepared by mechanical exfoliation and standard lithography procedures on thermally oxidized silicon varies significantly and seems to depend strongly on processing details and the substrate morphology. Moreover, ... More
Deceleration of Alpha Particles in the Solar Wind by Instabilities and the Rotational Force: Implications for Heating, Azimuthal Flow, and the Parker Spiral Magnetic FieldNov 17 2014Jun 16 2015Protons and alpha particles in the fast solar wind are only weakly collisional and exhibit a number of non-equilibrium features, including relative drifts between particle species. Two non-collisional mechanisms have been proposed for limiting differential ... More
Particle-in-cell study of the ion-to-electron sheath transitionApr 27 2016The form of a sheath near a small electrode, with bias changing from below to above the plasma potential is studied using 2D particle-in-cell (PIC) simulations. Five cases are studied: (A) an electrode biased more than the electron temperature ($T_e/e$) ... More
Interaction between dark matter sub-halos & galactic gaseous diskJul 12 2011Nov 04 2011We investigate the idea that the interaction of Dark Matter (DM) sub-halos with the gaseous disk of galaxies can be the origin for the observed holes and shells found in their neutral hydrogen (HI) distributions. We use high resolution hydrodynamic simulations ... More
Structural and electronic properties of $α,β$-(BEDT-TTF)$_2$I$_3$ and $κ$-(BEDT-TTF)$_2$X$_3$ (X=I,F,Br,Cl) organic charge transfer saltsMay 30 2017Aug 21 2017(BEDT-TFF)$_2$I$_3$ charge transfer salts are reported to show superconductivity and pressure induced quasi two-dimensional Dirac cones at the Fermi level. By performing state of the art ab initio calculations in the framework of density functional theory, ... More
The Worst Distortions of Astrometric Instruments and Orthonormal Models for Rectangular Fields of ViewOct 13 2011The non-orthogonality of algebraic polynomials of field coordinates traditionally used to model field-dependent corrections to astrometric measurements, gives rise to subtle adverse effects. In particular, certain field dependent perturbations in the ... More
Observations of the Ultraviolet-Bright Star Y453 in the Globular Cluster M4 (NGC 6121)Aug 03 2017We present a spectral analysis of the UV-bright star Y453 in M4. Model fits to the star's optical spectrum yield T_eff ~ 56,000 K. Fits to the star's FUV spectrum, obtained with the Cosmic Origins Spectrograph (COS) on board the Hubble Space Telescope, ... More
Discriminants of stable rank two sheaves on some general type surfacesDec 05 2018Jan 10 2019We prove sharp bounds on the discriminants of stable rank two sheaves on surfaces in three-dimensional projective space. The key technical ingredient is to study them as torsion sheaves in projective space via tilt stability in the derived category. We ... More
Reasoning about Unforeseen Possibilities During Policy LearningJan 10 2018Methods for learning optimal policies in autonomous agents often assume that the way the domain is conceptualised---its possible states and actions and their causal structure---is known in advance and does not change during learning. This is an unrealistic ... More
A New Channel for the Formation of Kinematically Decoupled Cores in Early-type galaxiesFeb 02 2015We present the formation of a Kinematically Decoupled Core (KDC) in an elliptical galaxy, resulting from a major merger simulation of two disk galaxies. We show that although the two progenitor galaxies are initially following a prograde orbit, strong ... More
A bound for the splitting of smooth Fano polytopes with many verticesSep 25 2014Aug 10 2015The classification of toric Fano manifolds with large Picard number corresponds to the classification of smooth Fano polytopes with large number of vertices. A smooth Fano polytope is a polytope that contains the origin in its interior such that the vertex ... More
FUSE, STIS, and Keck spectroscopic analysis of the UV-bright star vZ 1128 in M3 (NGC 5272)Jun 30 2015We present a spectral analysis of the UV-bright star vZ 1128 in M3 based on observations with the Far Ultraviolet Spectroscopic Explorer (FUSE), the Space Telescope Imaging Spectrograph (STIS), and the Keck HIRES echelle spectrograph. By fitting the H ... More
Star formation in mergers with cosmologically motivated initial conditionsJul 06 2015We use semi-analytic models and cosmological merger trees to provide the initial conditions for multi-merger numerical hydrodynamic simulations, and exploit these simulations to explore the effect of galaxy interaction and merging on star formation (SF). ... More
The effects of a hot gaseous halo in galaxy major mergersApr 01 2011Cosmological hydrodynamical simulations as well as observations indicate that spiral galaxies are comprised of five different components: dark matter halo, stellar disc, stellar bulge, gaseous disc and gaseous halo. While the first four components have ... More
Learning Based Segmentation of CT Brain Images: Application to Post-Operative Hydrocephalic ScansDec 11 2017Objective: Hydrocephalus is a medical condition in which there is an abnormal accumulation of cerebrospinal fluid (CSF) in the brain. Segmentation of brain imagery into brain tissue and CSF (before and after surgery, i.e. pre-op vs. postop) plays a crucial ... More
Quantitative Measures of Equity in Small GroupsOct 31 2017This project investigates how to quantitatively measure equity in small student groups. We follow several student groups to operationalize how discourse may be equitable or inequitable. The groups came from a two week, pre-college program that prepares ... More
Asymmetric percolation drives a double transition in sexual contact networksFeb 21 2017Jun 28 2017Zika virus (ZIKV) exhibits unique transmission dynamics in that it is concurrently spread by a mosquito vector and through sexual contact. We show that this sexual component of ZIKV transmission induces novel processes on networks through the highly asymmetric ... More
Ferroics: magnetic-compass lattice and optical phonon dispersions of dipolar crystalsDec 22 2005Jan 03 2006We report a simple safe and attractive pedagogic demonstration with magnetic compasses that facilitates an intuitive understanding of the concept that ferromagnetism and ferroelectricity do not result from dipole-dipole interactions alone. Phonon dispersion ... More
The effects of a hot gaseous halo on disc thickening in galaxy minor mergersAug 08 2011We employ hydrodynamical simulations to study the effects of dissipational gas physics on the vertical heating and thickening of disc galaxies during minor mergers. For the first time we present a suite of simulations that includes a diffuse, rotating, ... More
Can Gas prevent the Destruction of Thin Stellar Discs by Minor Mergers?Jun 03 2009Dec 14 2009We study the effect of dissipational gas physics on the vertical heating and thickening of disc galaxies during minor mergers. We produce a suite of minor merger simulations for Milky Way-like galaxies. This suite consists of collisionless simulations ... More
Leveraging the ALICE/L3 cavern for long-lived exoticsOct 08 2018Run 5 of the HL-LHC era (and beyond) may provide new opportunities to search for physics beyond the standard model (BSM) at interaction point 2 (IP2). In particular, taking advantage of the existing ALICE detector and infrastructure provides an opportunity ... More
Vacua and correlators in hyperbolic de Sitter spaceJan 31 2015Feb 23 2015We study the power - and bi -spectrum of vacuum fluctuations in a hyperbolic section of de Sitter space, comparing two states of physical interest: the Bunch-Davies and hyperbolic vacuum. We introduce a one -parameter family of de Sitter hyperbolic sections ... More
Sign-changing photon-mediated atom interactions in multimode cavity QEDOct 25 2018Sign-changing interactions constitute a crucial ingredient in the creation of frustrated many-body systems such as spin glasses. We present here the demonstration of a photon-mediated sign-changing interaction between Bose-Einstein condensed (BEC) atoms ... More
Path-by-path well-posedness of nonlinear diffusion equations with multiplicative noiseJul 11 2018We prove the path-by-path well-posedness of stochastic porous media and fast diffusion equations driven by linear, multiplicative noise. As a consequence, we obtain the existence of a random dynamical system. This solves an open problem raised in [Barbu, ... More
Quantum spin pumping with adiabatically modulated magnetic barrier'sMar 29 2003Dec 09 2003A quantum pump device involving magnetic barriers produced by the deposition of ferro magnetic stripes on hetero-structure's is investigated. The device for dc- transport does not provide spin-polarized currents, but in the adiabatic regime, when one ... More
On smooth Gorenstein polytopesMar 08 2013A Gorenstein polytope of index r is a lattice polytope whose r-th dilate is a reflexive polytope. These objects are of interest in combinatorial commutative algebra and enumerative combinatorics, and play a crucial role in Batyrev's and Borisov's computation ... More
Games and Meta-Games: Pricing Rules for Combinatorial MechanismsMar 20 2015In settings where full incentive-compatibility is not available, such as core-constraint combinatorial auctions and budget-balanced combinatorial exchanges, we may wish to design mechanisms that are as incentive-compatible as possible. This paper offers ... More
Homogenization of Hamilton-Jacobi equations with rough time dependenceFeb 16 2016We consider viscosity solutions of Hamilton-Jacobi equations with oscillatory spatial dependence and rough time dependence. The time dependence is in the form of the derivative of a continuous path that converges to a possibly nowhere-differentiable path, ... More
A simple proof of Brown's diagonalizability theoremOct 04 2010We present here a simple proof of Brown's diagonalizability theorem for certain elements of the algebra of a left regular band, including probability measures.
Yet another solution to the Burnside problem for matrix semigroupsNov 16 2008We use the kernel category to give a finiteness condition for semigroups. As a consequence we provide yet another proof that finitely generated periodic semigroups of matrices are finite.
Bipartite Euler systemsFeb 28 2012If E is an elliptic curve over Q and K is an imaginary quadratic field, there is an Iwasawa main conjecture predicting the behavior of the Selmer group of E over the anticyclotomic Z_p-extension of K. The main conjecture takes different forms depending ... More
Special cohomology classes for modular Galois representationsFeb 28 2012Building on ideas of Vatsal, Cornut proved a conjecture of Mazur asserting the generic nonvanishing of Heegner points on an elliptic curve E as one ascends the anticyclotomic Z_p-extension of a quadratic imaginary extension K/Q. In the present article ... More
Opportunities with top quarks at future circular collidersDec 04 2014We describe various studies relevant for top physics at future circular collider projects currently under discussion. We show how highly-massive top-antitop systems produced in proton-proton collisions at a center-of-mass energy of 100 TeV could be observed ... More
Beyond the Minimal Supersymmetric Standard Model: from theory to phenomenologyFeb 21 2012Thanks to the latest development in the field of Monte Carlo event generators and satellite programs allowing for a straightforward implementation of any beyond the Standard Model theory in those tools, studying the property of any softly-broken supersymmetric ... More
Transverse-momentum, threshold and joint resummations for slepton pair production at hadron collidersOct 10 2007We present precision calculations of the transverse-momentum spectrum and the invariant-mass distribution for slepton pair production at hadron colliders. We implement the transverse-momentum, threshold and joint resummation formalisms at the next-to-leading ... More
Slepton pair production at hadron collidersOct 24 2006In R-parity conserving supersymmetric models, sleptons are produced in pairs at hadron colliders. We show that measurements of the longitudinal single-spin asymmetry at possible polarization upgrades of existing colliders allow for a direct extraction ... More
Twisted derived equivalences for affine schemesNov 11 2013We show how work of Rickard and To\"en completely resolves the question of when two twisted affine schemes are derived equivalent.
On the integral Tate conjecture for finite fields and representation theoryApr 19 2015May 28 2015We describe a new source of counterexamples to the so-called integral Hodge and integral Tate conjectures. As in the other known counterexamples to the integral Tate conjecture over finite fields, ours are approximations of the classifying space of some ... More
Jet Charge with the ATLAS Detector using $\sqrt{s}=8$ TeV $pp$ Collision DataSep 01 2014The momentum-weighted sum of the charges of tracks associated to a jet provides an experimental handle on the electric charge of fundamental strongly-interacting particles. An overview of a study of this jet charge observable for jets produced in dijet ... More
Summary of progress on the Blaschke conjectureSep 05 2013Aug 03 2015The Blaschke conjecture claims that every compact Riemannian manifold whose injectivity radius equals its diameter is, up to constant rescaling, a compact rank one symmetric space. We summarize the intuition behind this problem, the proof that such manifolds ... More
Analogues elliptiques des nombres multizétasJan 14 2013Jan 12 2015We study functions of an elliptic parameter, which are defined as iterated integrals of elliptic functions. We establish their relation with the "elliptic associators" of our previous work, by means of a functional realization of Lie algebras appearing ... More
Holomorphic Cartan geometries on uniruled surfacesMay 24 2011We classify holomorphic Cartan geometries on every compact complex curve, and on every compact complex surface which contains a rational curve.
Computing Hybridization Networks for Multiple Rooted Binary Phylogenetic Trees by Maximum Acyclic Agreement ForestsAug 13 2014Dec 17 2015It is a known fact that, given two rooted binary phylogenetic trees, the concept of maximum acyclic agreement forests is sufficient to compute hybridization networks with minimum hybridization number. In this work, we demonstrate by first presenting an ... More
Einstein-aether as a quantum effective field theoryMay 14 2009The possibility that Lorentz symmetry is violated in gravitational processes is relatively unconstrained by experiment, in stark contrast with the level of accuracy to which Lorentz symmetry has been confirmed in the matter sector. One model of Lorentz ... More