Results for "Sebastian Acosta"

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Time reversal for radiative transport with applications to inverse and control problemsApr 10 2013Aug 03 2013In this paper we develop a time reversal method for the radiative transport equation to solve two problems: an inverse problem for the recovery of an initial condition from boundary measurements, and the exact boundary controllability of the transport ... More
A control approach to recover the wave speed (conformal factor) from one measurementJan 27 2014Jan 08 2015In this paper we consider the problem of recovering the conformal factor in a conformal class of Riemannian metrics from the boundary measurement of one wave field. More precisely, using boundary control operators, we derive an explicit equation satisfied ... More
Well-posedness for Photoacoustic Tomography with Fabry--Perot SensorsJun 03 2019In the mathematical analysis of photoacoustic imaging, it is usually assumed that the acoustic pressure (Dirichlet data) is measured on a detection surface. However, actual ultrasound detectors gather data of a different type. In this paper, we propose ... More
Recovery of the absorption coefficient in radiative transport from a single measurementAug 21 2013Feb 14 2015In this paper, we investigate the recovery of the absorption coefficient from boundary data assuming that the region of interest is illuminated at an initial time. We consider a sufficiently strong and isotropic, but otherwise unknown initial state of ... More
High order surface radiation conditions for time-harmonic waves in exterior domainsFeb 23 2017We formulate a new family of high order on-surface radiation conditions to approximate the outgoing solution to the Helmholtz equation in exterior domains. Motivated by the pseudo-differential expansion of the Dirichlet-to-Neumann operator developed by ... More
Multiwave imaging in an enclosure with variable wave speedJan 30 2015Apr 10 2015In this paper we consider the mathematical model of thermo- and photo-acoustic tomography for the recovery of the initial condition of a wave field from knowledge of its boundary values. Unlike the free-space setting, we consider the wave problem in a ... More
Recovery of Pressure and Wave Speed for Photoacoustic Imaging under a Condition of Relative UncertaintyMay 14 2019In this paper, we study the photoacoustic tomography problem for which we seek to recover both the initial state of the pressure field and the wave speed of the medium from the knowledge of a single boundary measurement. The goal is to propose practical ... More
Numerical method of characteristics for one-dimensional blood flowNov 20 2014Mar 27 2015Mathematical modeling at the level of the full cardiovascular system requires the numerical approximation of solutions to a one-dimensional nonlinear hyperbolic system describing flow in a single vessel. This model is often simulated by computationally ... More
Photoacoustic imaging taking into account thermodynamic attenuationFeb 04 2016Aug 24 2016In this paper we consider a mathematical model for photoacoustic imaging which takes into account attenuation due to thermodynamic dissipation. The propagation of acoustic (compressional) waves is governed by a scalar wave equation coupled to the heat ... More
FJRW-Rings and Landau-Ginzburg Mirror Symmetry in Two DimensionsJun 04 2009For any non-degenerate, quasi-homogeneous hypersurface singularity W and an admissible group of diagonal symmetries G, Fan, Jarvis, and Ruan have constructed a cohomological field theory which is a candidate for the mathematical structure behind the Landau-Ginzburg ... More
Source estimation with incoherent waves in random waveguidesAug 08 2014Feb 24 2015We study an inverse source problem for the acoustic wave equation in a random waveguide. The goal is to estimate the source of waves from measurements of the acoustic pressure at a remote array of sensors. The waveguide effect is due to boundaries that ... More
The DtN nonreflecting boundary condition for multiple scattering problems in the half-planeDec 28 2013The multiple-Dirichlet-to-Neumann (multiple-DtN) non-reflecting boundary condition is adapted to acoustic scattering from obstacles embedded in the half-plane. The multiple-DtN map is coupled with the method of images as an alternative model for multiple ... More
A weight-adjusted discontinuous Galerkin method for wave propagation in coupled elastic-acoustic mediaMay 22 2019This paper presents a high-order discontinuous Galerkin (DG) scheme for the simulation of wave propagation through coupled elastic-acoustic media. We use a first-order stress-velocity formulation, and derive a simple upwind-like numerical flux which weakly ... More
Valuations of Skew Quantum PolynomialsMar 07 2014Jul 26 2014In this paper we extend some results obtained by Artamonov and Sabitov for quantum polynomials to skew quantum polynomials and quasi-commutative bijective skew PBW extensions. Moreover, we find a counterexample to the conjecture proposed in [6]
On the multi-frequency inverse source problem in heterogeneous mediaDec 28 2013The inverse source problem where an unknown source is to be identified from the knowledge of its radiated wave is studied. The focus is placed on the effect that multi-frequency data has on establishing uniqueness. In particular, it is shown that data ... More
Generalized Lennard-Jones Potentials, SUSYQM and Differential Galois TheoryMar 03 2018Sep 19 2018In this paper we start with proving that the Schr\"odinger equation (SE) with the classical $12-6$ Lennard-Jones (L-J) potential is nonintegrable in the sense of the differential Galois theory (DGT), for any value of energy; i.e., there are no solutions ... More
Stimulated emission depletion microscopy with diamond silicon-vacancy centersJul 19 2019Stimulated emission depletion (STED) microscopy is a technique that can image fluorescent samples with a spatial resolution superior to the diffraction limit. However the resolution is still limited by the photostability of available fluorophores. Here, ... More
Bishop-Phelps-Bollobás property for positive operators when the domain is $L_\infty $Jul 19 2019We prove that the class of positive operators from $L_\infty (\mu)$ to $Y$ has the Bishop-Phelps-Bollob\'as property for any positive measure $\mu$, whenever $Y$ is a uniformly monotone Banach lattice with a weak unit. The same result also holds for the ... More
Liouvillian Propagators, Riccati Equation and Differential Galois TheoryApr 21 2013Jun 13 2013In this paper a Galoisian approach to build propagators through Riccati equations is presented. The main result corresponds to the relationship between the Galois integrability of the linear Schr\"odinger equation and the virtual solvability of the differential ... More
Bishop-Phelps-Bollobás property for positive operators between classical Banach spacesMay 30 2019We prove that the class of positive operators from $L_\infty (\mu)$ to $L_1 (\nu)$ has the Bishop-Phelps-Bollob\'as property for any positive measures $\mu$ and $\nu$. The same result also holds for the pair $(c_0, \ell_1)$. We also provide an example ... More
XPath Node Selection over Grammar-Compressed TreesNov 21 2013XML document markup is highly repetitive and therefore well compressible using grammar-based compression. Downward, navigational XPath can be executed over grammar-compressed trees in PTIME: the query is translated into an automaton which is executed ... More
Some tastings in Morales-Ramis TheoryOct 16 2018In this paper we present a short material concerning to some results in Morales-Ramis theory, which relates two different notions of integrability: Integrability of Hamiltonian Systems through Liouville Arnold Theorem and Integrability of Linear Differential ... More
Differential Galois Groups and Representation of Quivers for Seismic Models with Constant Hessian of Square of SlownessDec 13 2016The trajectory of energy is modeled by the solution of the Eikonal equation, which can be solved by solving a Hamiltonian system. This system is amenable of treatment from the point view of the theory of Differential Algebra. In particular, by Morales-Ramis ... More
Liouvillian Solutions of Schrödinger Equation with Polynomial Potentials using Gröbner BasisOct 22 2018May 12 2019The main aim of this paper is the presentation of a new methodology to obtain Liouvillian solutions of stationary one dimensional Schr\"odinger equation with quasi-solvable polynomial potentials through the using of differential Galois theory and Gr\"obner ... More
Secular and Rotational Light Curves of 6478 GaultJun 24 2019Jul 11 2019We obtained 877 images of active asteroid 6478 Gault on 41 nights from January 10th to June 8th, 2019, using several telescopes. We created the phase, secular and rotational light curves of Gault, from which several physical parameters can be derived. ... More
The Pinpoint Comets: 133P/Elst-Pizarro, 249P/LINEAR, 331P/Gibbs, 62412 and 6478 GaultJul 01 2019From two Active Asteroid (AA) known in 1979 we have advanced to 37 members at the beginning of 2019. More surprisingly, in the first three months of 2019 five new members were added to the list, one of them, 6478 Gault, with a curious, out of the ordinary ... More
Fast and Tiny Structural Self-Indexes for XMLDec 28 2010XML document markup is highly repetitive and therefore well compressible using dictionary-based methods such as DAGs or grammars. In the context of selectivity estimation, grammar-compressed trees were used before as synopsis for structural XPath queries. ... More
On an analogue of a Brauer theorem for fusion categoriesMar 16 2015In this paper we prove an analogue of Brauer's theorem for faithful objects in fusion categories. Other notions, such as the order and the index associated to faithful objects of fusion categories are also discussed. We show that the index of a faithful ... More
Resolutions for unit groups of ordersSep 28 2016We present a general algorithm for constructing a free resolution for unit groups of orders in semisimple rational algebras. The approach is based on computing a contractible $G$-complex employing the theory of minimal classes of quadratic forms and Opgenorth's ... More
Continuity of discrete homomorphisms of diffeomorphism groupsJul 16 2013Jul 15 2016Let $M$ and $N$ be two closed $C^{\infty}$ manifolds and let $\text{Diff}_c(M)$ denote the group of $C^{\infty}$ diffeomorphisms isotopic to the identity. We prove that any (discrete) group homomorphism between $\text{Diff}_c(M)$ and $\text{Diff}_c(N)$ ... More
Theoretical overview of b->s hadronic decaysFeb 10 2010A wealth of data on hadronic b -> s transitions is available from the B-factories and will be improved at the LHCb experiment and possible future super-B-factories. I review the theory of these decays as it pertains to the search for physics beyond the ... More
SUSY beyond minimal flavour violationOct 29 2007Dec 06 2007We review aspects of the phenomenology of the MSSM with non-minimal flavour violation, including a discussion of important constraints and the sensitivity to fundamental scales.
Particle Filters in Robotics (Invited Talk)Dec 12 2012This presentation will introduce the audience to a new, emerging body of research on sequential Monte Carlo techniques in robotics. In recent years, particle filters have solved several hard perceptual robotic problems. Early successes were limited to ... More
Introduction to Measurement Space and Application to Operationally Useful Entanglement and Mode EntanglementApr 27 2010Aug 28 2010We introduce the idea that the knowable quantum reality depends not only on the state but also on measurements. Mathematically, we map the states from the ordinary Hilbert space into new states in what we call the measurement space. The state vectors ... More
Cluster Transformations from Bipartite Field TheoriesJan 02 2013Oct 17 2013Bipartite field theories (BFTs) are a new class of 4d N=1 quantum field theories defined by bipartite graphs on bordered Riemann surfaces. In this paper we derive, purely in terms of the gauge theory, the cluster transformations of face weights under ... More
Experimental Challenges of the European Strategy for Particle PhysicsSep 30 2013Oct 07 2013In planning for the Phase II upgrades of CMS and ATLAS major considerations are: 1)being able to deal with degradation of tracking and calorimetry up to the radiation doses to be expected with an integrated luminosity of 3000 $fb^{-1}$ and 2)maintaining ... More
Neutron Production and Zero Degree Calorimeter Acceptance at LHCDec 22 2009May 10 2010We calculate cross sections for the far forward LHC detectors to be used for luminosity measurement. A simple model, based on a parametrization of available inclusive neutron data and the assumption that 2 arm rates in non-diffractive events are uncorrelated, ... More
Diffractive J/$ψ$ production in Ultraperipheral AuAu Collisions at RHICOct 31 2005We report on the first measurement of diffractive J/psi production in Ultraperipheral Au+Au collisions at \sqrt{s_{NN}}=200 GeV.
MusicMood: Predicting the mood of music from song lyrics using machine learningNov 01 2016Sentiment prediction of contemporary music can have a wide-range of applications in modern society, for instance, selecting music for public institutions such as hospitals or restaurants to potentially improve the emotional well-being of personnel, patients, ... More
Why Is Dual-Pivot Quicksort Fast?Nov 03 2015Sep 28 2016I discuss the new dual-pivot Quicksort that is nowadays used to sort arrays of primitive types in Java. I sketch theoretical analyses of this algorithm that offer a possible, and in my opinion plausible, explanation why (a) dual-pivot Quicksort is faster ... More
Two-Qubit Pulse Gate for the Three-Electron Double Quantum Dot QubitSep 04 2014Jan 22 2015The three-electron configuration of gate-defined double quantum dots encodes a promising qubit for quantum information processing. I propose a two-qubit entangling gate using a pulse-gated manipulation procedure. The requirements for high-fidelity entangling ... More
Universality of ac-conduction in anisotropic disordered systems: An effective medium approximation studyFeb 03 2004Apr 12 2005Anisotropic disordered system are studied in this work within the random barrier model. In such systems the transition probabilities in different directions have different probability density functions. The frequency-dependent conductivity at low temperatures ... More
Machine learning-assisted discovery of GPCR bioactive ligandsDec 16 2018While G-protein coupled receptors (GPCRs) constitute the largest class of membrane proteins, structures and endogenous ligands of a large portion of GPCRs remain unknown. Due to the involvement of GPCRs in various signaling pathways and physiological ... More
Post-Newtonian dynamics at order 1.5 in the Vlasov-Maxwell systemFeb 13 2006We study the dynamics of many charges interacting with the Maxwell field. The particles are modeled by means of non-negative distribution functions $f^+$ and $f^-$ representing two species of charged matter with positive and negative charge, respectively. ... More
Equivalence Problems for Tree Transducers: A Brief SurveyMay 22 2014The decidability of equivalence for three important classes of tree transducers is discussed. Each class can be obtained as a natural restriction of deterministic macro tree transducers (MTTs): (1) no context parameters, i.e., top-down tree transducers, ... More
A spectral curve approach to Lawson symmetric CMC surfaces of genus 2Sep 14 2012Apr 11 2013Minimal and CMC surfaces in $S^3$ can be treated via their associated family of flat $\SL(2,\C)$-connections. In this the paper we parametrize the moduli space of flat $\SL(2,\C)$-connections on the Lawson minimal surface of genus 2 which are equivariant ... More
Discrete knot energiesMar 08 2016The present chapter gives an overview on results for discrete knot energies. These discrete energies are designed to make swift numerical computations and thus open the field to computational methods. Additionally, they provide an independent, geometrically ... More
Totally geodesic submanifolds of the exceptional Riemannian symmetric spaces of rank 2Sep 08 2008The present article is the final part of a series on the classification of the totally geodesic submanifolds of the irreducible Riemannian symmetric spaces of rank 2. After this problem has been solved for the 2-Grassmannians in my previous papers cited ... More
Toric Poisson Ideals in Cluster AlgebrasSep 15 2010Feb 29 2012This paper investigates the Poisson geometry associated to a cluster algebra over the complex numbers, and its relationship to compatible torus actions. We show, under some assumptions, that each Noetherian cluster algebra has only finitely many torus ... More
Bernoulli Percolation on random TessellationsSep 15 2016We generalize the standard site percolation model on the $d$-dimensional lattice to a model on random tessellations of $\mathbb R^d$. We prove the uniqueness of the infinite cluster by adapting the Burton-Keane argument \cite{burton1989density}, develop ... More
For which positive $p$ is the integral Menger curvature $\mathcal{M}_{p}$ finite for all simple polygons?Feb 02 2012In this brief note we show that the integral Menger curvature $\mathcal{M}_{p}$ is finite for all simple polygons if and only if $p\in (0,3)$. For the intermediate energies $\mathcal{I}_{p}$ and $\mathcal{U}_{p}$ we obtain the analogous result for $p\in ... More
Properties of the Dirac spectrum on three dimensional lens spacesApr 13 2015Aug 14 2015We present a spectral rigidity result for the Dirac operator on lens spaces. More specifically, we show that each homogeneous lens space and each three dimensional lens space $L(q;p)$ with $q$ prime is completely characterized by its Dirac spectrum in ... More
Conformally Flat Circle Bundles over SurfacesFeb 26 2009We classify conformally flat Riemannian $3-$manifolds which possesses a free isometric $S^1-$action.
On Kesten's Multivariate Choquet-Deny LemmaFeb 21 2013Mar 14 2014Let $d >1$ and $(A_n)_{n \ge 1}$ be a sequence of independent identically distributed random matrices with nonnegative entries and no zero column. This induces a Markov chain $M_n = A_n M_{n-1}$ on the cone of d-vectors with nonnegative entries. We study ... More
The third cohomology group classifies crossed module extensionsNov 15 2009Sep 29 2010We give an elementary proof of the well-known fact that the third cohomology group H^3(G, M) of a group G with coefficients in an abelian G-module M is in bijection to the set Ext^2(G, M) of equivalence classes of crossed module extensions of G with M. ... More
Hölder-Zygmund Estimates for Degenerate Parabolic SystemsJul 19 2013We consider energy solutions of the inhomogeneous parabolic $p$-Laplacien system $\partial_t u-\text{div}(|D u|^{p-2}D u)=-\text{div} g$. We show in the case $p\geq 2$ that if the right hand side $g$ is locally in $L^\infty(\text{BMO})$, then $u$ is locally ... More
Group theoretical independence of $\ell$-adic Galois representationsJan 17 2017Let $K/\mathbb{Q}$ be a finitely generated field of characteristic zero and $X/K$ a smooth projective variety. Fix $q\in\mathbb{N}$. For every prime number $\ell$ let $\rho_\ell$ be the representation of $\mathrm{Gal}(K)$ on the \'etale cohomology group ... More
A spectral theory for simply periodic solutions of the sinh-Gordon equationJul 29 2016In this work a spectral theory for 2-dimensional, simply periodic, complex-valued solutions u of the sinh-Gordon equation is developed. Spectral data for such solutions are defined (following Hitchin and Bobenko) and the space of spectral data is described ... More
Equivalences between localisations of categories provided by replacementsOct 09 2018We give a characterisation of functors whose induced functor on the level of localisations is an equivalence and where the isomorphism inverse is induced by some kind of replacements such as projective resolutions or cofibrant replacements.
BEACH 2014 Theory SummaryJan 30 2015I summarize key aspects of the quest for physics beyond the Standard Model in flavour physics as discussed at the BEACH 2014 conference in Birmingham.
A Note on kappa-Diagonal Surface StatesAug 31 2004We classify all twist-even squeezed states in string field theory which are diagonal in the kappa-basis and simultaneously surface states. For this purpose, we derive a consistency condition for the maps defining kappa-diagonal surface states. It restricts ... More
WZ and W+jets production at large transverse momenta beyond NLOMay 28 2013Jun 09 2013We present a study of higher order QCD corrections beyond NLO to processes with electroweak vector bosons. We focus on the regions of high transverse momenta of commonly used differential distributions. We employ the LoopSim method, combined with NLO ... More
The Yang-Mills Vacuum Wave Functional in 2+1 DimensionsApr 28 2014Aug 23 2014We investigate Yang-Mills theory in 2+1 dimensions in the Schroedinger representation. The Schroedinger picture is interesting because it is well suited to explore properties of the vacuum state in the non-perturbative regime. Yet, not much analytical ... More
On a symmetry of Müger's centralizer for the Drinfeld double of a semisimple Hopf algebraDec 11 2013In this paper we prove a formula that relates M\"uger's centralizer in the category of representations of a factorizable Hopf algebra to the notion of Hopf kernel of a representation of the dual Hopf algebra. Using this relation we obtain a complete description ... More
Improved Information Gain Estimates for Decision Tree InductionJun 18 2012Ensembles of classification and regression trees remain popular machine learning methods because they define flexible non-parametric models that predict well and are computationally efficient both during training and testing. During induction of decision ... More
Spectroscopic Measurements Using the H1 and ZEUS DetectorsJun 08 2005Results on spectroscopy from the H1 and ZEUS collaborations are presented. The main focus is to search for baryon states which could be interpreted as pentaquarks. This includes states decaying to K^0_sp and K^0_s\bar{p}, \Xi\pi and D*p. In addition an ... More
T-Duality in Lattice Regularized Sigma ModelsMay 29 1998It is shown that when the underlying sigma model of bosonic string theory is written in terms of single-valued fields, which live in the covering space of the target space, Abelian T-duality survives lattice regularization of the world-sheet. The projection ... More
$L^{p}-L^{q}$ theory for holomorphic functions of perturbed first order Dirac operatorsMar 21 2014Sep 09 2014The aim of the article is to prove $L^{p}-L^{q}$ off-diagonal estimates and $L^{p}-L^{q}$ boundedness for operators in the functional calculus of certain perturbed first order differential operators of Dirac type for with $p\le q$ in a certain range of ... More
Predictive and Self Triggering for Event-based State EstimationSep 23 2016Event-based state estimation can achieve estimation quality comparable to traditional time-triggered methods, but with a significantly lower number of samples. In networked estimation problems, this reduction in sampling instants does, however, not necessarily ... More
QCD and Jets at Hadron CollidersNov 30 2015Sep 13 2016We review various aspects of jet physics in the context of hadron colliders. We start by discussing the definitions and properties of jets and recent development in this area. We then consider the question of factorization for processes with jets, in ... More
The S-Matrix of superstring field theoryJul 29 2015We show that the classical S-matrix calculated from the recently proposed superstring field theories give the correct perturbative S-matrix. In the proof we exploit the fact that the vertices are obtained by a field redefinition in the large Hilbert space. ... More
Frustrated polaritonsFeb 05 2016Artificially engineered light-matter systems constitute a novel, versatile architecture for the quantum simulation of driven, dissipative phase transitions and non-equilibrium quantum many-body systems. Here, we review recent experimental as well as theoretical ... More
Inverse of the String Theory KLT KernelOct 13 2016The field theory Kawai-Lewellen-Tye (KLT) kernel, which relates scattering amplitudes of gravitons and gluons, turns out to be the inverse of a matrix whose components are bi-adjoint scalar partial amplitudes. In this note we propose an analogous construction ... More
An overview of gradient descent optimization algorithmsSep 15 2016Gradient descent optimization algorithms, while increasingly popular, are often used as black-box optimizers, as practical explanations of their strengths and weaknesses are hard to come by. This article aims to provide the reader with intuitions with ... More
Bound for preperiodic points for maps with good reductionAug 20 2016Sep 12 2016Let $K$ be a number field and let $\phi$ in $K(z)$ be a rational function of degree $d\geq 2$. Let $S$ be the places of bad reduction for $\phi$ (including the archimedan places). Let $Per(\phi,K)$, $PrePer(\phi, K)$, and $Tail(\phi,K)$ be the set of ... More
Dirichlet-to-Neumann and Neumann-to-Dirichlet methods for bound states of the Helmholtz equationFeb 25 2011Two methods for computing bound states of the Helmholtz equation in a finite domain are presented. The methods are formulated in terms of the Dirichlet-to-Neumann (DtN) and Neumann-to-Dirichlet (NtD) surface integral operators. They are adapted from the ... More
Data Assimilation: The Schrödinger PerspectiveJul 22 2018Dec 02 2018Data assimilation addresses the general problem of how to combine model-based predictions with partial and noisy observations of the process in an optimal manner. This survey focuses on sequential data assimilation techniques using probabilistic particle-based ... More
Generalized pathway entropy and its applications in diffusion entropy analysis and fractional calculusFeb 28 2014We presented background information about various entropies in the literature. The pathway idea of Mathai (2005) is shown to be inferable from the maximization of a certain generalized entropy measure and established connections to outstanding problems ... More
Black hole entropy and thermodynamics from symmetriesApr 22 2002Apr 29 2002Given a boundary of spacetime preserved by a Diff(S^{1}) sub-algebra, we propose a systematic method to compute the zero mode and the central extension of the associated Virasoro algebra of charges. Using these values in the Cardy formula, we may derive ... More
Lorentz invariance of scalar field action on $κ$-Minkowski space-timeJan 04 2005We construct field theory on noncommutative $\kappa$-Minkowski space-time. Having the Lorentz action on the noncommutative space-time coordinates we show that the field lagrangian is invariant. We show that noncommutativity requires replacing the Leibnitz ... More
Post-Newtonian approximation of the Vlasov-Nordström systemOct 23 2004We study the Nordstr\"om-Vlasov system which describes the dynamics of a self-gravitating ensemble of collisionless particles in the framework of the Nordstr\"om scalar theory of gravitation. If the speed of light $c$ is considered as a parameter, it ... More
Adiabatic limits of Seifert fibrations, Dedekind sums, and the diffeomorphism type of certain 7-manifoldsAug 29 2011We extend the adiabatic limit formula for eta-invariants by Bismut-Cheeger and Dai to Seifert fibrations. Our formula contains a new contribution from the singular fibres that takes the form of a generalised Dedekind sum. As an application, we compute ... More
Poisson and quantum geometry of acyclic cluster algebrasOct 22 2012We prove that certain acyclic cluster algebras over the complex numbers are the coordinate rings of holomorphic symplectic manifolds. We also show that the corresponding quantum cluster algebras have no non-trivial prime ideals. This allows us to give ... More
Dynamical sensitivity of recurrence and transience of branching random walksJul 27 2009Dec 07 2009Consider a sequence of i.i.d. random variables $X_n$ where each random variable is refreshed independently according to a Poisson clock. At any fixed time $t$ the law of the sequence is the same as for the sequence at time 0 but at random times almost ... More
Lawson's genus two minimal surface and meromorphic connectionsSep 28 2010We investigate the Lawson genus $2$ surface by methods from integrable system theory. We prove that the associated family of flat connections comes from a family of flat connections on a $4-$punctured sphere. We describe the symmetries of the holonomy ... More
Braided Symmetric Algebras of Simple $U_q(sl_2)$-Modules and Their GeometrySep 15 2010Feb 29 2012In the present paper we prove decomposition formulae for the braided symmetric powers of simple modules over the quantized enveloping algebra $U_q(sl_2)$; natural quantum analogues of the classical symmetric powers of a module over a complex semisimple ... More
A non-relativistic Model of Plasma Physics Containing a Radiation Reaction TermApr 20 2016While a fully relativistic collisionless plasma is modeled by the Vlasov-Maxwell system a good approximation in the non-relativistic limit is given by the Vlasov-Poisson system. We modify the Vlasov-Poisson system so that damping due to the relativistic ... More
Resolutions for unit groups of ordersSep 28 2016Dec 05 2016We present a general algorithm for constructing a free resolution for unit groups of orders in semisimple rational algebras. The approach is based on computing a contractible $G$-complex employing the theory of minimal classes of quadratic forms and Opgenorth's ... More
Lifting SU(3)-structures to nearly parallel G_{2}-structuresJul 13 2007Hitchin shows that half-flat SU(3)-structures on a 6-dimensional manifold M can be lifted to parallel G_{2}-structure on the product $M\times\mathbb{R}$. We show that Hitchin's approach can also be used to construct nearly parallel G_{2}-structures by ... More
On the irreducible representations of generalized quantum doublesFeb 20 2012A description of all the irreducible representations of generalized quantum doubles associated to skew pairings of semisimple Hopf algebras is given. In particular a description of the irreducible representations of semisimple Drinfeld doubles is obtained. ... More
Backward-Backward Splitting in Hadamard SpacesSep 23 2013Sep 30 2013The backward-backward algorithm is a tool for finding minima of a regularization of the sum of two convex functions in Hilbert spaces. We generalize this setting to Hadamard spaces and prove the convergence of an error-tolerant version of the backward-backward ... More
Mellin moments of heavy flavor contributions to F_2(x,Q^2) at NNLOOct 16 2009This thesis is concerned with the calculation of fixed moments of the O(a_s^3) heavy flavor contributions to the Wilson coefficients of the structure function F_2(x,Q^2) in the limit Q^2 >> m^2, neglecting power corrections. The massive Wilson coefficients ... More
Accurate variational electronic structure calculations with the density matrix renormalization groupMay 06 2014During the past 15 years, the density matrix renormalization group (DMRG) has become increasingly important for ab initio quantum chemistry. The underlying matrix product state (MPS) ansatz is a low-rank decomposition of the full configuration interaction ... More
Turbulent spectra in real-time gauge field evolutionDec 12 2008We investigate ultraviolet fixed points in the real-time evolution of non-Abelian gauge fields. Classical-statistical lattice simulations reveal equal-time correlation functions with a spectral index 3/2. Analytical understanding of this result is achieved ... More
Supersymmetry beyond minimal flavour violationAug 14 2008Nov 18 2008We review the sources and phenomenology of non-minimal flavour violation in the MSSM. We discuss in some detail the most important theoretical and experimental constraints, as well as promising observables to look for supersymmetric effects at the LHC ... More
On strategies for determination and characterization of the underlying eventSep 04 2010Sep 22 2010We discuss the problem of the separation and description of the underlying event (UE) within two existing approaches to UE measurement: the "traditional" method, widely used at Tevatron, and a recently proposed jet-area/median method. A simple toy model ... More
Bipartite Field Theories: from D-Brane Probes to Scattering AmplitudesJul 03 2012Dec 20 2012We introduce and initiate the investigation of a general class of 4d, N=1 quiver gauge theories whose Lagrangian is defined by a bipartite graph on a Riemann surface, with or without boundaries. We refer to such class of theories as Bipartite Field Theories ... More
The Chordal Loewner Equation and Monotone Probability TheoryMay 21 2016Jun 21 2016In [5], O. Bauer interpreted the chordal Loewner equation in terms of non-commutative probability theory. We follow this perspective and identify the chordal Loewner equations as the non-autonomous versions of evolution equations for semigroups in monotone ... More
Second-order perturbation theory for 3He and pd scattering in pionless EFTSep 11 2016This work implements pionless effective field theory with the two-nucleon system expanded around the unitarity limit at second order perturbation theory. The expansion is found to converge well. All Coulomb effects are treated in perturbation theory, ... More
A Projection to the Pure Spinor SpaceFeb 02 2012This article is based on a talk given at the Memorial Conference for Maximilian Kreuzer at the ESI in Vienna and contains a compact summary of a recent collaboration with P.A. Grassi. A non-linear projection from the space of SO(10) Weyl spinors to the ... More