Results for "Felipe A. La Porta"

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Versatile Hall magnetometer with variable sensitivity assembly for characterization of the magnetic properties of nanoparticlesMay 14 2019Jun 17 2019A Hall magnetometer with variable sensitivity is constructed to measure the magnetic properties of magnetic nanoparticles manufactured by different methods. This novel magnetometer can also be used to measure bulk materials and samples in liquids. The ... More
A multifrequency angular power spectrum analysis of the Leiden polarization surveysJan 17 2006Jun 29 2006The Galactic synchrotron emission is expected to be the most relevant source of astrophysical contamination in cosmic microwave background polarization measurements, at least at frequencies < 100 GHz and at angular scales > 30'. We present a multifrequency ... More
Navigation strategies of motor proteins on decorated tracksSep 08 2015Motor proteins display widely different stepping patterns as they move on microtubule tracks, from the deterministic linear or helical motion performed by the protein kinesin to the uncoordinated random steps made by dynein. How these different strategies ... More
Conformational mechanism for the stability of microtubule-kinetochore attachmentsJul 21 2014Regulating the stability of microtubule(MT)-kinetochore attachments is fundamental to avoiding mitotic errors and ensure proper chromosome segregation during cell division. While biochemical factors involved in this process have been identified, its mechanics ... More
Cholesterol impairment contributes to neuroserpin aggregationMay 15 2017Intraneural accumulation of misfolded proteins is a common feature of several neurodegenerative pathologies including Alzheimer's and Parkinson's diseases, and Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB). FENIB is a rare disease ... More
TeamPhone: Networking Smartphones for Disaster RecoveryJun 10 2016Mar 26 2017In this paper, we investigate how to network smartphones for providing communications in disaster recovery. By bridging the gaps among different kinds of wireless networks, we have designed and implemented a system called TeamPhone, which provides smartphones ... More
Cooperative Data Offload in Opportunistic Networks: From Mobile Devices to InfrastructureJun 10 2016Mar 26 2017Opportunistic mobile networks consisting of intermittently connected mobile devices have been exploited for various applications, such as computational offloading and mitigating cellular traffic load. In contrast to existing work, in this paper, we focus ... More
Mechanical Properties of Growing Melanocytic Nevi and the Progression to MelanomaApr 16 2014Melanocytic nevi are benign proliferations that sometimes turn into malignant melanoma in a way that is still unclear from the biochemical and genetic point of view. Diagnostic and prognostic tools are then mostly based on dermoscopic examination and ... More
Universal statistics of epithelial tissue topologyOct 23 2017Cells forming various epithelial tissues have a strikingly universal distribution for the number of their edges. It is generally assumed that this topological feature is predefined by the statistics of individual cell divisions in growing tissue but existing ... More
A statistical analysis of a Galactic all sky survey at 1.4 GHzJul 04 2006Radio surveys at frequencies of about 1 GHz allow to map the synchrotron emission in a frequency range where (except for very low Galactic latitudes or towards localized regions) it dominates over the other radio components. New all sky total intensity ... More
CXCR6, a Newly Defined Biomarker of Tissue-Specific Stem Cell Asymmetric Self-Renewal, Identifies More Aggressive Human Melanoma Cancer Stem CellsAug 28 2013Background: A fundamental problem in cancer research is identifying the cell type that is capable of sustaining neoplastic growth and its origin from normal tissue cells. Recent investigations of a variety of tumor types have shown that phenotypically ... More
Anomaly non-renormalization in interacting Weyl semimetalsJul 01 2019For a class of interacting 3D lattice Weyl semimetals, we prove that the quadratic response of the quasi-particle flow between the Weyl points to an external electromagnetic field, which is the condensed-matter analogue of the chiral anomaly, is exactly ... More
Bursts of activity in collective cell migrationOct 25 2016Dense monolayers of living cells display intriguing relaxation dynamics, reminiscent of soft and glassy materials close to the jamming transition, and migrate collectively when space is available, as in wound healing or in cancer invasion. Here we show ... More
An observational test for correlations between cosmic rays and magnetic fieldsMay 02 2012Sep 19 2013We derive the magnitude of fluctuations in total synchrotron intensity in the Milky Way and M33, from both observations and theory under various assumption about the relation between cosmic rays and interstellar magnetic fields. Given the relative magnitude ... More
Khintchine's Theorem with random fractionsAug 09 2017Dec 17 2018We prove versions of Khintchine's Theorem (1924) for approximations by rational numbers whose numerators lie in randomly chosen sets of integers, and we explore the extent to which the monotonicity assumption can be removed. Roughly speaking, we show ... More
A Simple Algorithm for Computing the Document ArrayDec 21 2018Mar 11 2019We present a simple algorithm for computing the document array given the string collection and its suffix array as input. Our algorithm runs in linear time using constant additional space for strings from constant alphabets.
Higher cohomology of parabolic actions on certain homogeneous spacesDec 14 2013We show that for a parabolic R^d-action on a compact quotient of PSL(2,R)^d, the cohomologies in degrees 1 through d-1 trivialize, and we give the obstructions to solving the degree-d coboundary equation, along with bounds on Sobolev norms of primitives. ... More
Khintchine types of translated coordinate hyperplanesMay 28 2014Jan 14 2015There has been great interest in developing a theory of "Khintchine types" for manifolds embedded in Euclidean space, and considerable progress has been made for curved manifolds. We treat the case of translates of coordinate hyperplanes, decidedly flat ... More
A lattice gauge theory model for grapheneMay 06 2011In this Ph.D. thesis a model for graphene in presence of quantized electromagnetic interactions is introduced. The zero and low temperature properties of the model are studied using rigorous renormalization group methods and lattice Ward identities. In ... More
Studio della misura di Sinai-Ruelle-Bowen in un sistema sempliceFeb 08 2010In this thesis we discuss some applications of the theory of Anosov systems to nonequilibrium statistical mechanics. In particular, we perform a perturbative check of the Gallavotti-Cohen fluctuation relation for a simple Anosov system; we find that the ... More
The derived Riemann-Hilbert correspondenceMar 11 2017In this short paper we prove a derived version of the Riemann-Hilbert correspondence of Deligne and Simpson. Our generalization is twofold: on one side we consider families of representations of the full homotopy type of a smooth analytic space $X$ in ... More
Universal property of triangulated derivators via Keller's towersDec 08 2015Apr 19 2017In his thesis B. Keller solved the universal problem of the extension of an exact category to its (bounded) derived category by introducing the notions of tower of exact and triangulated categories and proving the universal property in this setting. In ... More
The Popescu-Gabriel theorem for triangulated categoriesJun 29 2007Feb 15 2008The Popescu-Gabriel theorem states that each Grothendieck abelian category is a localization of a module category. In this paper, we prove an analogue where Grothendieck abelian categories are replaced by triangulated categories which are well generated ... More
Generalized Magnetofluid Connections in Relativistic MagnetohydrodynamicsFeb 26 2015The concept of magnetic connections is extended to non-ideal relativistic magnetohydrodynamical plasmas. Adopting a general set of equations for relativistic magnetohydrodynamics including thermal-inertial, thermal electromotive, Hall and current-inertia ... More
Single Past Null Geodesic in the Lemaitre-Tolman-Bondi CosmologyDec 17 2013This work provides a general discussion of the spatially inhomogeneous Lema\^itre-Tolman-Bondi (LTB) cosmology, as well as its basic properties and many useful relevant quantities, such as the cosmological distances. We apply the concept of the single ... More
Gravitational electromotive force in magnetic reconnection around Schwarzschild black holesMar 04 2019We analytically explore the effects of the gravitational electromotive force on magnetic reconnection around Schwarzschild black holes through a generalized general-relativistic magnetohydrodynamic model that retains two-fluid effects. It is shown that ... More
Recurrence to shrinking targets on typical self-affine fractalsSep 26 2014Oct 19 2015We explore the problem of finding the Hausdorff dimension of the set of points that recur to shrinking targets on a self-affine fractal. To be exact, we study the dimension of a certain related symbolic recurrence set. In many cases this set is equivalent ... More
Weighing the Sun with five photographsJun 28 2019With only five photographs of the Sun at different dates we show that the mass of Sun can be calculated by using a telescope, a camera, and the third Kepler's law. With the photographs we are able to calculate the distance from Sun to Earth at different ... More
A class of compact Poincare-Einstein manifolds: properties and constructionAug 15 2008We develop a geometric and explicit construction principle that generates classes of Poincare-Einstein manifolds, and more generally almost Einstein manifolds. Almost Einstein manifolds satisfy a generalisation of the Einstein condition; they are Einstein ... More
A sub-product construction of Poincare-Einstein metricsAug 02 2006Dec 21 2006Given any two Einstein (pseudo-)metrics, with scalar curvatures suitably related, we give an explicit construction of a Poincar\'e-Einstein (pseudo-)metric with conformal infinity the conformal class of the product of the initial metrics. We show that ... More
Estimating the Moon to Earth radius ratio with a smartphone, a telescope and an eclipseJul 19 2019On January 20th, 2019, a total lunar eclipse was possible to be observed in Santiago, Chile. Using a smartphone attached to a telescope, photographs of the phenomenon were taken. With Earth's shadow on those images, and using textbook geometry, a simple ... More
ATLAS IBL Pixel UpgradeApr 11 2011The upgrade for ATLAS detector will undergo different phase towards super-LHC. The first upgrade for the Pixel detector will consist of the construction of a new pixel layer which will be installed during the first shutdown of the LHC machine (LHC phase-I ... More
New non-Noetherian Symmetries and Multi-Hamiltonian Structures for the Toda LatticeJun 09 2009New symmetry transformations for the n-dimensional Toda lattice are presented. Their existence allows for the construction of several first order Lagrangian structures associated to them. The multi-Hamiltonian structures are derived from Lagrangians in ... More
Spinning particles coupled to gravityOct 27 2016Recent experimental work has determined that free falling $^{87}$Rb atoms on Earth, with vertically aligned spins, follow geodesics, thus apparently ruling out spin--gravitation interactions. It is showed that while some spinning matter models coupled ... More
Electromagnetic redshift in anisotropic cosmologiesJan 16 2018May 08 2018The redshift of light is calculated for an anisotropic cosmological spacetime. Two different approaches are considered. In the first one, electromagnetic waves are modeled using the geometrical optics (high--frequency) approximation. This approach considers ... More
Characterization of the errors of the FMM in particle simulationsSep 10 2008The Fast Multipole Method (FMM) offers an acceleration for pairwise interaction calculation, known as $N$-body problems, from $\mathcal{O}(N^2)$ to $\mathcal{O}(N)$ with $N$ particles. This has brought dramatic increase in the capability of particle simulations ... More
Supersymmetric Majorana Quantum CosmologiesJun 09 2015Oct 20 2015The Einstein equations for an isotropic and homogeneous Friedmann--Robertson--Walker Universe in the presence of a quintessence scalar field are shown to be described in a unified way, formally identical to the dynamics of a relativistic particle moving ... More
Do electromagnetic waves always propagate along null geodesics?Aug 23 2016Sep 08 2017We find exact solutions to Maxwell equations written in terms of four-vector potentials in non--rotating, as well as in G\"odel and Kerr spacetimes. We show that Maxwell equations can be reduced to two uncoupled second-order differential equations for ... More
Correspondence between dark energy quantum cosmology and Maxwell equationsMay 20 2019A Friedmann-Robertson-Walker cosmology with dark energy can be modelled using a quintessence field. That system is equivalent to a relativistic particle moving on a two-dimensional conformal spacetime. The quantized version of that theory can lead to ... More
Non--geodesic circular motion of massive spinning test bodiesMar 11 2018Oct 03 2018Recent interest on studying possible violations of the Equivalence Principle has led to the development of space satellite missions testing it for bodies moving on circular orbits around Earth. This experiment establishes that the validity of the Equivalence ... More
The Sato-Tate Distribution in Thin Parametric Families of Elliptic CurvesSep 10 2015Mar 07 2018We obtain new results concerning the Sato-Tate conjecture on the distribution of Frobenius traces over single and double parametric families of elliptic curves. We consider these curves for values of parameters having prescribed arithmetic structure: ... More
The effect of spin magnetization in the damping of electron plasma oscillationsMay 14 2010The effect of spin of particles in the propagation of plasma waves is studied using a semi-classical kinetic theory for a magnetized plasma. We focus in the simple damping effects for the electrostatic wave modes besides Landau damping. Without taking ... More
Magnetic field generation in curved spacetimesMar 23 2011Oct 08 2012Using the generally covariant magnetofluid formalism for a hot plasma, a new curvature (of space time) driven mechanism for generating seed vorticity/magnetic field is presented. The "battery" owes its origin to the interaction between gravity (epitomized ... More
Stability window and mass-radius relation for magnetized strange quark starsDec 01 2008The stability of magnetized strange quark matter (MSQM) is investigated within the phenomenological MIT bag model, taking into account the variation of the relevant input parameters, namely, the strange quark mass, baryon density, magnetic field and bag ... More
Diamagnetic field states in cosmological plasmasDec 22 2018Using a generally covariant Electro-Vortic (magnetofluid) formalism for relativistic plasmas, the dynamical evolution of a generalized vorticity (a combination of the magnetic and kinematic parts) is studied in a cosmological context. We derive macroscopic ... More
On the image of polynomials evaluated on incidence algebras: a counter-example and a solutionFeb 21 2019Apr 20 2019In this paper, we investigate the subset obtained by evaluations of a fixed multilinear polynomial on a given algebra. We provide an example of a multilinear polynomial, whose image is not a vector subspace; namely, the product of two commutators need ... More
Quasinormal Modes, Stability Analysis and Absorption Cross Section for 4-dimensional Topological Lifshitz Black HoleMay 02 2012Nov 27 2012We study scalar perturbations in the background of a Topological Lifshitz black hole in four dimensions. We compute analytically the quasinormal modes and from these modes we show that Topological Lifshitz black hole is stable. On the other hand, we compute ... More
A Very Heavy Sneutrino as Viable Thermal Dark Matter Candidate in $U(1)'$ Extensions of the MSSMOct 31 2017May 03 2019We study the Standard Model singlet ("right-handed") sneutrino $\tilde \nu_R$ dark matter in a class of $U(1)'$ extensions of the MSSM that originate from the breaking of the $E_6$ gauge group. These models, which are referred to as UMSSM, contain three ... More
The contribution of magnetic monopoles to ponderomotive forces in plasmasJan 08 2018May 17 2018It is well--known that when magnetic monopoles are introduced in plasma equations the propagation of electromagnetic waves is modified. This occurs because of Maxwell equations acquire a symmetrical structure due to the existence of electric and magnetic ... More
Classes of forms Witt equivalent to a second trace form over fields of characteristic twoOct 09 2004Let F be a field of characteristic two. We determine all non-hyperbolic quadratic forms over F that are Witt equivalent to a second trace form.
Borel summability of $φ^{4}_{4}$ planar theory via multiscale analysisFeb 10 2010Mar 03 2010We review the issue of Borel summability in the framework of multiscale analysis and renormalization group, by discussing a proof of Borel summability of the $\phi^{4}_4$ massive euclidean planar theory; this result is not new, since it was obtained by ... More
Quantum theory within the probability calculus: a there-you-go theorem and partially exchangeable modelsMar 06 2018Mar 07 2018"Ever since the advent of modern quantum mechanics in the late 1920's, the idea has been prevalent that the classical laws of probability cease, in some sense, to be valid in the new theory. [...] The primary object of this presentation is to show that ... More
Categorification of two-dimensional cohomological Hall algebrasMar 18 2019In the present paper, we provide a full categorification, at the level of stable $\infty$-categories, of two-dimensional cohomological Hall algebras of curves and surfaces. This is achieved by producing a suitable derived enhancement of the relevant moduli ... More
Generalization of the second trace form of central simple algebras in characteristic twoOct 09 2004Let F be a field with characteristic two. We generalize the second trace form for central simple algebras with odd degree over F. We determine the second trace form and the Arf invariant and Clifford invariant for tensor products of central simple algebras. ... More
Analytification of mapping stacksDec 21 2018Derived mapping stacks are a fundamental source of examples of derived enhancements of classical moduli problems. For instance, they appear naturally in Gromov-Witten theory and in some branches of geometric representation theory. In this paper, we show ... More
Derived Non-archimedean analytic Hilbert spaceJun 17 2019In this short paper we combine the representability theorem introduced in [17, 18] with the theory of derived formal models introduced in [2] to prove the existence representability of the derived Hilbert space RHilb(X) for a separated k-analytic space ... More
Cross correlation and time-lag between cosmic ray intensity and solar activity during solar cycles 21, 22 and 23Jun 04 2019In the present paper a systematic study is carried out to validate the similarity or degree of relationship between daily terrestrial cosmic rays intensity and three characteristics of about evolution of solar corona, like a number of sunspots and flare ... More
Infinitesimal and square-zero extensions of simplicial algebrasOct 14 2013Oct 04 2015We introduce the notions of infinitesimal extension and square-zero extension in the context of simplicial commutatie algebras. We next investigate their mutual relationship and we show that the Postnikov tower of a simplicial commutative algebra is built ... More
Geometrical Unification of Gravitation and Dark Energy: The Universe as a Relativistic ParticleMar 10 2014The Lagrangian, the Hamilton--Jacobi equation and the Schr\"{o}dinger, Dirac and Klein--Gordon equations for the Friedmann--Robertson--Walker--Quintessence (FRWQ) system are presented and solved exactly for different interesting scenarios. The classical ... More
Quantization of the Universe as a Dirac Particle: Geometrical Unification of Gravitation, Dark Energy and MultiversesMar 10 2014Aug 22 2017A Friedmann--Robertson--Walker Universe is studied with a dark energy component represented by a quintessence field. The Lagrangian for this system, hereafter called the Friedmann--Robertson--Walker--quintessence (FRWq) system, is presented. It is shown ... More
How to obtain efficient GPU kernels: an illustration using FMM & FGT algorithmsSep 17 2010Mar 01 2011Computing on graphics processors is maybe one of the most important developments in computational science to happen in decades. Not since the arrival of the Beowulf cluster, which combined open source software with commodity hardware to truly democratize ... More
PetFMM--A dynamically load-balancing parallel fast multipole libraryMay 15 2009Fast algorithms for the computation of $N$-body problems can be broadly classified into mesh-based interpolation methods, and hierarchical or multiresolution methods. To this last class belongs the well-known fast multipole method (FMM), which offers ... More
Spinning massive test particles in cosmological and general static spherically symmetric spacetimesAug 20 2013Feb 06 2014A Lagrangian formalism is used to study the motion of a spinning massive particle in Friedmann--Robertson--Walker and G\"odel spacetimes, as well as in a general Schwarzschild-like spacetime and in static spherically symmetric conformally flat spacetimes. ... More
Convex Integration Solutions for the Geometrically Non-linear Two-Well Problem with Higher Sobolev RegularityMay 29 2019In this article we discuss higher Sobolev regularity of convex integration solutions for the geometrically non-linear two-well problem. More precisely, we construct solutions to the differential inclusion $\nabla u\in K$ subject to suitable affine boundary ... More
Geometry of maximum-entropy proofs: stationary points, convexity, Legendre transforms, exponential familiesJun 13 2017This note is a geometric commentary on maximum-entropy proofs. Its purpose is to illustrate the geometric structures involved in such proofs, to explain more in detail why the maximization of the entropy can be turned into the minimization of a potential ... More
Versatile Hall magnetometer with variable sensitivity assembly for characterization of the magnetic properties of nanoparticlesMay 14 2019A Hall magnetometer with variable sensitivity is constructed to measure the magnetic properties of magnetic nanoparticles manufactured by different methods. This novel magnetometer can also be used to measure bulk materials and samples in liquids. The ... More
Square-free class sizes in products of groupsMar 24 2017We obtain some structural properties of a factorised group $G = AB$, given that the conjugacy class sizes of certain elements in $A\cup B$ are not divisible by $p^2$, for some prime $p$. The case when $G = AB$ is a mutually permutable product is especially ... More
Discriminative training for Convolved Multiple-Output Gaussian processesFeb 07 2015Multi-output Gaussian processes (MOGP) are probability distributions over vector-valued functions, and have been previously used for multi-output regression and for multi-class classification. A less explored facet of the multi-output Gaussian process ... More
Portable, high-performance containers for HPCApr 11 2017Building and deploying software on high-end computing systems is a challenging task. High performance applications have to reliably run across multiple platforms and environments, and make use of site-specific resources while resolving complicated software-stack ... More
Do cancer cells undergo phenotypic switching? The case for imperfect cancer stem cell markersAug 28 2013The identification of cancer stem cells in vivo and in vitro relies on specific surface markers that should allow to sort cancer cells in phenotypically distinct subpopulations. Experiments report that sorted cancer cell populations after some time tend ... More
Zeros of irreducible characters in factorised groupsMar 01 2018An element $g$ of a finite group $G$ is said to be vanishing in $G$ if there exists an irreducible character $\chi$ of $G$ such that $\chi(g)=0$; in this case, $g$ is also called a zero of $G$. The aim of this paper is to obtain structural properties ... More
Prime power indices in factorised groupsMay 02 2017Let the group $G = AB$ be the product of the subgroups $A$ and $B$. We determine some structural properties of $G$ when the $p$-elements in $A\cup B$ have prime power indices in $G$, for some prime $p$. More generally, we also consider the case that all ... More
Products of groups and class sizes of $π$-elementsDec 21 2018We provide structural criteria for some finite factorised groups $G = AB$ when the conjugacy class sizes in $G$ of certain $\pi$-elements in $A\cup B$ are either $\pi$-numbers or $\pi'$-numbers, for a set of primes $\pi$. In particular, we extend for ... More
Gaia-DR2 distance to the W3 Complex in the Perseus ArmMay 21 2019The Perseus Arm is the closest Galactic spiral arm from the Sun, offering an excellent opportunity to study in detail its stellar population. However, its distance has been controversial with discrepancies by a factor of two. Kinematic distances are in ... More
Derived non-archimedean analytic spacesJan 05 2016We propose a derived version of non-archimedean analytic geometry. Intuitively, a derived non-archimedean analytic space consists of an ordinary non-archimedean analytic space equipped with a sheaf of derived rings. Such a naive definition turns out to ... More
Convective nonlocal Cahn-Hilliard equations with reaction termsJun 06 2014May 13 2015We introduce and analyze the nonlocal variants of two Cahn-Hilliard type equations with reaction terms. The first one is the so-called Cahn-Hilliard-Oono equation which models, for instance, pattern formation in diblock-copolymers as well as in binary ... More
Derived non-archimedean analytic spacesJan 05 2016Feb 07 2017We propose a derived version of non-archimedean analytic geometry. Intuitively, a derived non-archimedean analytic space consists of an ordinary non-archimedean analytic space equipped with a sheaf of derived rings. Such a naive definition turns out to ... More
Higher analytic stacks and GAGA theoremsDec 16 2014Jul 28 2016We develop the foundations of higher geometric stacks in complex analytic geometry and in non-archimedean analytic geometry. We study coherent sheaves and prove the analog of Grauert's theorem for derived direct images under proper morphisms. We define ... More
Mass-radius relation for magnetized strange quark starsJan 22 2010Apr 06 2010We review the stability of magnetized strange quark matter (MSQM) within the phenomenological MIT bag model, taking into account the variation of the relevant input parameters, namely, the strange quark mass, baryon density, magnetic field and bag parameter. ... More
Helioseismic Holography of Simulated Sunspots: dependence of the travel time on magnetic field strength and Wilson depressionMay 25 2017Improving methods for determining the subsurface structure of sunspots from their seismic signature requires a better understanding of the interaction of waves with magnetic field concentrations. We aim to quantify the impact of changes in the internal ... More
Generalized Magnetofluid Connections in Pair PlasmasOct 20 2015We extend the magnetic connection theorem of ideal magnetohydrodynamics to nonideal relativistic pair plasmas. Adopting a generalized Ohm's law, we prove the existence of generalized magnetofluid connections that are preserved by the plasma dynamics. ... More
External memory BWT and LCP computation for sequence collections with applicationsMay 17 2018We propose an external memory algorithm for the computation of the BWT and LCP array for a collection of sequences. Our algorithm takes the amount of available memory as an input parameter, and tries to make the best use of it by splitting the input collection ... More
Synthetic polarimetric spectra from stellar prominencesOct 28 2016Stellar prominences detected in rapidly rotating stars serve as probes of the magnetism in the corona of cool stars. We have synthesized the temporal evolution of the Stokes profiles generated in the He I 10830 and 5876 A triplets during the rotation ... More
Impact of Matter Density Profile Shape on Non-Standard Interactions at DUNESep 25 2018Nov 15 2018We discuss the impact of matter density profile shape on the determination of nonstandard neutrino matter interactions (NSI) in the context of the long baseline accelerator experiments such as Deep Underground Neutrino Experiment (DUNE). The primary scientific ... More
Electromagnetic energy within single-resonance chiral metamaterial spheresMar 04 2013We derive an exact expression for the time-averaged electromagnetic energy inside a chiral dispersive sphere irradiated by a plane wave. The dispersion relations correspond to a chiral metamaterial consisting of uncoupled single-resonance helical resonators. ... More
Flavor-dependent CP violation and electroweak baryogenesis in supersymmetric theoriesAug 26 2002Oct 29 2002We analyze electroweak baryogenesis in supersymmetric theories with flavor-dependent CP-violating phases. We generalize the standard approach to include the flavor dependence of the CP-violating sources and obtain an analytical approximate expression ... More
Observability inequalities on measurable sets for the Stokes system and applicationsAug 23 2017In this paper, we establish spectral inequalities on measurable sets of positive Lebesgue measure for the Stokes operator, as well as an observability inequalities on space-time measurable sets of positive measure for non-stationary Stokes system. Furthermore, ... More
The group generated by Riordan involutionsMar 19 2018We prove that any element in the group generated by the Riordan involutions is the product of at most four of them. We also give a description of this subgroup as a semidirect product of a special subgroup of the commutator subgroup and the Klein four-group. ... More
Group gradings on finite dimensional incidence algebrasMay 21 2019In this work, we classify the group gradings on finite-dimensional incidence algebras over a field, where the field has characteristic zero, or the characteristic is greater than the dimension of the algebra, or the grading group is abelian. Moreover, ... More
Unlearning and Seyab's theorem: a dialogue about updating probabilityFeb 03 2018This dialogue explores the possibility of updating a probability as a consequence of unlearning, reversing the role of prior and posterior probabilities.
Derived Hom spaces in rigid analytic geometryJan 23 2018We construct a derived enhancement of Hom spaces between rigid analytic spaces. It encodes the hidden deformation-theoretic informations of the underlying classical moduli space. The main tool in our construction is the representability theorem in derived ... More
Representability theorem in derived analytic geometryApr 06 2017Dec 02 2018We prove the representability theorem in derived analytic geometry. The theorem asserts that an analytic moduli functor is a derived analytic stack if and only if it is compatible with Postnikov towers, has a global analytic cotangent complex, and its ... More
Can Li-rich giants eject shells? Assembling the lithium puzzle in K giantsSep 24 2012The existence of K giant stars with high Li abundance continues to challenge the standard theory of stellar evolution. All recent extensive surveys in the Galaxy show the same result: about 1 % of the mainly normal slow rotating K giants are Li rich. ... More
Unification of couplings and soft supersymmetry breaking terms in 4D superstring modelsJan 12 1994Feb 03 1994We consider the predictions for the hierarchy of mass scales, the fine structure constant, the radii of compactification and the soft SUSY breaking terms which follow if SUSY breaking is triggered by a gaugino condensate.
On d-Walk Regular GraphsMar 30 2013Let G be a graph with set of vertices 1,...,n and adjacency matrix A of size nxn. Let d(i,j)=d, we say that f_d:N->N is a d-function on G if for every pair of vertices i,j and k>=d, we have a_ij^(k)=f_d(k). If this function f_d exists on G we say that ... More
Six combinatorial clases of maximal convex tropical polyhedraMay 18 2012Oct 31 2012In this paper we bring together tropical linear algebra and convex 3-dimensional bodies. We show how certain convex 3-dimensional bodies having 20 vertices and 12 facets can be encoded in a $4\times 4$ integer zero-diagonal matrix $A$. A tropical tetrahedron ... More
The Initial Mass Function of Early-type Galaxies: no correlation with [Mg/Fe]Feb 11 2015The Initial Mass Function (IMF) of early-type galaxies (ETGs) has been found to feature systematic variations by both dynamical and spectroscopic studies. In particular, spectral line strengths, based on gravity-sensitive features, suggest an excess of ... More
From Integer Sequences to Block Designs via Counting Walks in GraphsFeb 05 2013We define numbers of the type Oj(N) and Ej(N) and the corresponding integer sequences. We prove that these integer sequences, e.g., SO(N) and SE(N) correspond to the number of odd and even walks in complete graphs. We then prove that there is a unique ... More
Maximum walk entropy implies walk regularityJun 19 2014Feb 01 2019The notion of walk entropy $S^V(G,\beta)$ for a graph $G$ at the inverse temperature $\beta$ was put forward recently by Estrada et al. (2014) \cite{6}. It was further proved by Benzi \cite{1} that a graph is walk-regular if and only if its walk entropy ... More
Reconstructing the distribution of haloes and mock galaxies below the resolution limit in cosmological simulationsDec 14 2012Jul 18 2013We present a method for populating dark matter simulations with haloes of mass below the resolution limit. It is based on stochastically sampling a field derived from the density field of the halo catalogue, using constraints from the conditional halo ... More