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Results for "Thomas Eisenbarth"

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RELOAD+REFRESH: Abusing Cache Replacement Policies to Perform Stealthy Cache AttacksApr 12 2019Caches have become the prime method for unintended information extraction across logical isolation boundaries. Even Spectre and Meltdown rely on the cache side channel, as it provides great resolution and is widely available on all major CPU platforms. ... More
MemJam: A False Dependency Attack against Constant-Time Crypto ImplementationsNov 21 2017Cache attacks exploit memory access patterns of cryptographic implementations. Constant-Time implementation techniques have become an indispensable tool in fighting cache timing attacks. These techniques engineer the memory accesses of cryptographic operations ... More
CacheZoom: How SGX Amplifies The Power of Cache AttacksMar 20 2017Aug 20 2017In modern computing environments, hardware resources are commonly shared, and parallel computation is widely used. Parallel tasks can cause privacy and security problems if proper isolation is not enforced. Intel proposed SGX to create a trusted execution ... More
DeepCloak: Adversarial Crafting As a Defensive Measure to Cloak ProcessesAug 03 2018Over the past decade, side-channels have proven to be significant and practical threats to modern computing systems. Recent attacks have all exploited the underlying shared hardware. While practical, mounting such a complicated attack is still akin to ... More
PerfWeb: How to Violate Web Privacy with Hardware Performance EventsMay 12 2017The browser history reveals highly sensitive information about users, such as financial status, health conditions, or political views. Private browsing modes and anonymity networks are consequently important tools to preserve the privacy not only of regular ... More
MicroWalk: A Framework for Finding Side Channels in BinariesAug 16 2018Jan 07 2019Microarchitectural side channels expose unprotected software to information leakage attacks where a software adversary is able to track runtime behavior of a benign process and steal secrets such as cryptographic keys. As suggested by incremental software ... More
CacheShield: Protecting Legacy Processes Against Cache AttacksSep 06 2017Cache attacks pose a threat to any code whose execution flow or memory accesses depend on sensitive information. Especially in public clouds, where caches are shared across several tenants, cache attacks remain an unsolved problem. Cache attacks rely ... More
SPOILER: Speculative Load Hazards Boost Rowhammer and Cache AttacksMar 01 2019Modern microarchitectures incorporate optimization techniques such as speculative loads and store forwarding to improve the memory bottleneck. The processor executes the load speculatively before the stores, and forwards the data of a preceding store ... More
Undermining User Privacy on Mobile Devices Using AINov 27 2018Over the past years, literature has shown that attacks exploiting the microarchitecture of modern processors pose a serious threat to the privacy of mobile phone users. This is because applications leave distinct footprints in the processor, which can ... More
AutoLock: Why Cache Attacks on ARM Are Harder Than You ThinkMar 28 2017Attacks on the microarchitecture of modern processors have become a practical threat to security and privacy in desktop and cloud computing. Recently, cache attacks have successfully been demonstrated on ARM based mobile devices, suggesting they are as ... More
Did we learn from LLC Side Channel Attacks? A Cache Leakage Detection Tool for Crypto LibrariesSep 05 2017This work presents a new tool to verify the correctness of cryptographic implementations with respect to cache attacks. Our methodology discovers vulnerabilities that are hard to find with other techniques, observed as exploitable leakage. The methodology ... More
Spherical 2-designs and lattices from Abelian groupsOct 29 2015Apr 06 2017We consider lattices generated by finite Abelian groups. We prove that such a lattice is strongly eutactic, which means the normalized minimal vectors of the lattice form a spherical 2-design, if and only if the group is of odd order or if it is a power ... More
How deals with discrete data for the reduction of simulation models using neural networkJun 10 2009Simulation is useful for the evaluation of a Master Production/distribution Schedule (MPS). Also, the goal of this paper is the study of the design of a simulation model by reducing its complexity. According to theory of constraints, we want to build ... More
Spectral Correlations in the Crossover Transition from a Superposition of Harmonic Oscillators to the Gaussian Unitary EnsembleJul 20 1998We compute the spectral correlation functions for the transition from a harmonic oscillator towards the Gaussian Unitary Ensemble (GUE). We use a variant of the supersymmetry method to obtain analytical results in a fast and elegant way. In contrast to ... More
Thermodynamic formalism for transport coefficients with an application to the shear modulus and shear viscosityDec 07 2016We discuss Onsager's thermodynamic formalism for transport coefficients and apply it to the calculation of the shear modulus and shear viscosity of a monodisperse system of repulsive particles. We focus on the concept of extensive "distance" and intensive ... More
On the quantifier-free dynamic complexity of ReachabilityJun 13 2013Jan 28 2015The dynamic complexity of the reachability query is studied in the dynamic complexity framework of Patnaik and Immerman, restricted to quantifier-free update formulas. It is shown that, with this restriction, the reachability query cannot be dynamically ... More
Sélection de la structure d'un perceptron multicouches pour la réduction dun modèle de simulation d'une scierieDec 05 2008Simulation is often used to evaluate the relevance of a Directing Program of Production (PDP) or to evaluate its impact on detailed sc\'enarii of scheduling. Within this framework, we propose to reduce the complexity of a model of simulation by exploiting ... More
Infinite reduced words and the Tits boundary of a Coxeter groupJan 05 2013Sep 18 2014Let (W,S) be a finite rank Coxeter system with W infinite. We prove that the limit weak order on the blocks of infinite reduced words of W is encoded by the topology of the Tits boundary of the Davis complex X of W. We consider many special cases, including ... More
And the winner is: galaxy massFeb 24 2011The environment is known to affect the formation and evolution of galaxies considerably best visible through the well-known morphology-density relationship. We study the effect of environment on the evolution of early-type galaxies for a sample of 3,360 ... More
Leptogenesis from right-handed neutrino decays to right-handed leptonsJun 16 2006We investigate what would be the consequences for leptogenesis of the existence of a charged SU(2)_L singlet scalar delta^+. If such a scalar particle exists, it allows the right-handed neutrinos to couple not only to left-handed lepton and Higgs doublets ... More
Leptogenesis: beyond the minimal type I seesaw scenarioDec 12 2012Numerous recent evidences for neutrino masses have established the leptogenesis mechanism as a very natural possible explanation for the baryon asymmetry of the Universe. The explicit realization of this mechanism depends on the neutrino mass model considered. ... More
Abundance ratios in hierarchical galaxy formationJan 18 1999The chemical enrichment and stellar abundance ratios of galaxies which form in a hierarchical clustering scheme are calculated. For this purpose I adopt the star formation histories (SFH) as they are delivered by semi-analytic models in Kauffmann (1996}. ... More
Group Schemes with $\mathbb F_q$-ActionFeb 07 2015We prove an equivalence of categories, generalizing the equivalence between commutative flat group schemes in characteristic $p$ with trivial Verschiebung and Dieudonn\'e $\mathbb F_p$-modules to group schemes with an action of $\mathbb F_q$.
Confidence Level Computation for Combining Searches with Small StatisticsFeb 05 1999This article describes an efficient procedure for computing approximate confidence levels for searches for new particles where the expected signal and background levels are small enough to require the use of Poisson statistics. The results of many independent ... More
Flashes of light below the dripping faucet: an optical signal from capillary oscillations of water dropsFeb 11 2009Feb 18 2009Falling water drops from a dripping faucet, illuminated from above, exhibit a row of bright strips of light, a few centimeters apart at a fixed distance below the faucet. Flash photographs of the drops show that they are oblate in shape when the flashes ... More
Isotope effect in the presence of a pseudogapNov 09 1999We investigate the question whether the unusual doping dependence of the isotope exponent observed in underdoped high-Tc superconductors might be related to another unusual phenomenon observed in these systems: the pseudogap phenomenon. Within different ... More
The Light-Cone Effective PotentialDec 17 2002Feb 03 2003It is shown how to calculate simple vacuum diagrams in light-cone quantum field theory. As an application, I consider the one-loop effective potential of phi^4 theory. The standard result is recovered both with and without the inclusion of zero modes ... More
Abundances of stars in different Galactic subsystemsDec 16 2013This is a brief overview of the elemental abundance patterns that have been observed in the different Galactic stellar populations. Main focus is on studies that are based on high-resolution spectra of dwarf and subgiant stars, and in some cases red giant ... More
Characterisation of the Galactic thick diskAug 23 2013Thick disks appear to be common in external large spiral galaxies and our own Milky Way also hosts one. The existence of a thick disk is possibly directly linked to the formation history of the host galaxy and if its properties is known it can constrain ... More
Continuum tree limit for the range of random walks on regular treesSep 22 2005Let $b$ be an integer greater than 1 and let $W^{\ee}=(W^{\ee}_n; n\geq 0)$ be a random walk on the $b$-ary rooted tree $\U_b$, starting at the root, going up (resp. down) with probability $1/2+\epsilon$ (resp. $1/2 -\epsilon$), $\epsilon \in (0, 1/2)$, ... More
Path decompositions for real Levy processesSep 22 2005Let $X$ be a real L\'evy process and let $\Xpos $ be the process conditioned to stay positive. We assume that $ 0 $ is regular for $(-\infty, 0)$ and $(0, +\infty) $ with respect to $X$. Using elementary excursion theory arguments, we provide a simple ... More
Supersymmetry and the generalized Lichnerowicz formulaJan 14 1996A classical result in differential geometry due to Lichnerowicz [8] is concerned with the decomposition of the square of Dirac operators defined by Clifford connections on a Clifford module ${\cal E}$\ over a Riemannian manifold $M$. Recently, this formula ... More
A Note on the Wodzicki ResidueJun 23 1995Jan 20 1996In this note we explain the relationship of the Wodzicki residue of (certain powers of) an elliptic differential operator $P$\ acting on sections of a complex vector bundle $E$\ over a closed compact manifold $M$\ and the asymptotic expansion of the trace ... More
Classification of Finite Spectral TriplesJan 16 1997Jan 20 1997It is known that the spin structure on a Riemannian manifold can be extended to noncommutative geometry using the notion of a spectral triple. For finite geometries, the corresponding finite spectral triples are completely described in terms of matrices ... More
Theory and Phenomenology of Dirac LeptogenesisDec 26 2007Dirac leptogenesis, in which neutrinos are purely Dirac and develop small but nonzero effective masses without the aid of the see-saw mechanism, provides an interesting alternative to the standard leptogenesis picture. Here we review the theory and phenomenology ... More
Requirements to Detect the Monoenergetic Photon Signature of Thermal Cold Dark Matter in PeV-Scale Split SupersymmetryMar 24 2005Split supersymmetry scenarios with PeV-scale scalar masses circumvent many of the restrictions on supersymmetry coming from experimental limits on CP violation, flavor-changing neutral currents, and the Higgs boson mass. We consider the situation where ... More
Potentials Unbounded BelowNov 28 2010Apr 26 2011Continuous interpolates are described for classical dynamical systems defined by discrete time-steps. Functional conjugation methods play a central role in obtaining the interpolations. The interpolates correspond to particle motion in an underlying potential, ... More
Three fermions in a boxOct 13 2008I calculate finite-volume effects for three identical spin-1/2 fermions in a box assuming short-ranged repulsive interactions of `natural size'. This analysis employs standard perturbation theory in powers of 1/L, where L^3 is the volume of the box. I ... More
Clusters and halos in light nucleiOct 15 2012The fermionic molecular dynamics approach uses Gaussian wave packets as single-particle basis states. Many-body basis states are Slater determinants projected on parity, angular momentum and total linear momentum. The wave-packet basis is very flexible ... More
Inelastic scattering in a local polaron model with quadratic coupling to bosonsMar 10 2009We calculate the inelastic scattering probabilities in the wide band limit of a local polaron model with quadratic coupling to bosons. The central object is a two-particle Green function which is calculated exactly using a purely algebraic approach. Compared ... More
Invisible stimuli, implicit thresholds: Why invisibility judgments cannot be interpreted in isolationJun 04 2013May 22 2014Some studies of unconscious cognition rely on judgments of participants stating that they have "not seen" the critical stimulus (e.g., in a masked-priming experiment). Trials in which participants gave "not-seen" judgments are then treated as those where ... More
More on functional and quantitative versions of the isoperimetric inequalitySep 14 2016This paper deals with the famous isoperimetric inequality. In a first part, we give some new functional form of the isoperimetric inequality, and in a second part, we give a quantitative form with a remainder term involving Wasserstein distance of the ... More
Approximation properties of isogeometric function spaces on singularly parameterized domainsJul 29 2015We study approximation error bounds of isogeometric function spaces on a specific type of singularly parameterized domains. In this context an isogeometric function is the composition of a piecewise rational function with the inverse of a piecewise rational ... More
On the commutator of unit quaternions and the numbers 12 and 24Jan 26 2011May 28 2012The quaternions are non-commutative. The deviation from commutativity is encapsulated in the commutator of unit quaternions. It is known that the k-th power of the commutator is null-homotopic if and only if k is divisible by 12. The main purpose of this ... More
Top Quark PhysicsApr 06 1999In this contribution I review the physics of top quarks at a future Linear Collider. Main emphasis is put on the process e+ e- to ttbar close to threshold. Different physical observables, their sensitivity to the basic parameters and their theoretical ... More
Odd orders in Shor's factoring algorithmAug 12 2014Jan 13 2015Shor's factoring algorithm (SFA) finds the prime factors of a number, $N=p_1 p_2$, exponentially faster than the best known classical algorithm. Responsible for the speed-up is a subroutine called the quantum order finding algorithm (QOFA) which calculates ... More
From Special Geometry to Black Hole Partition FunctionsDec 22 2008These notes are based on lectures given at the Erwin-Schrodinger Insitut in Vienna in 2006/07 and at the 2007 School on Attractor Mechanism in Frascati. Lecture I: special geometry from the superconformal point of view. Lecture II: black hole attractor ... More
Orbifold Compactifications with continuous Wilson linesOct 28 1993Nov 08 1993We identify the untwisted moduli of heterotic orbifold compactifications for the case, when the gauge twist is realized by a rotation. The Wilson lines are found to have both continuous and discrete parts. For the case of the standard Z(3) orbifold we ... More
Solutions of the Einstein-Dirac Equation on Riemannian 3-Manifolds with Constant Scalar CurvatureFeb 22 2000This paper contains a classification of all 3-dimensional manifolds with constant scalar curvature $S \not= 0$ that carry a non-trivial solution of the Einstein-Dirac equation.
Isomonodromic deformation of q-difference equations and confluenceFeb 16 2015We study isomonodromic deformation of Fuchsian linear q-difference systems. Furthermore, we are looking of the behaviour of the Birkhoff connexion matrix when q goes to $1$. We use our results to study the convergence of the Birkhoff connexion matrix ... More
Solution of the Mayan Calendar EnigmaJan 13 2016Jan 19 2016The Mayan Codices, bark-paper books from the Late Postclassic period (1300 to 1521 CE) contain many tables correlating ritual practices to astronomical cycles. This demonstrates the achievements of Mayan mathematics as applied to time measurements characterized ... More
Laminations géodésiques plates mesuréesNov 29 2013In [Mor], we have introduced a notion of flat laminations on surfaces endowed with a flat structure, similar to geodesic laminations on hyperbolic surfaces. Here is a sequel to this article that aims at defining transversal measures on flat laminations ... More
Parity check systems of nonlinear codes over finite commutative Frobenius ringsApr 24 2016The concept of parity check matrices of linear binary codes has been extended by Heden [9] to parity check systems of nonlinear binary codes. In the present paper we extend this concept to parity check systems of nonlinear codes over finite commutative ... More
Nonnegative Rank vs. Binary RankMar 24 2016Motivated by (and using tools from) communication complexity, we investigate the relationship between the following two ranks of a $0$-$1$ matrix: its nonnegative rank and its binary rank (the $\log$ of the latter being the unambiguous nondeterministic ... More
A note on the best invariant estimation of continuous probability distributions under mean square lossOct 21 2015We consider the nonparametric estimation problem of continuous probability distribution functions. For the integrated mean square error we provide the statistic corresponding to the best invariant estimator proposed by Aggarwal (1955) and Ferguson (1967). ... More
White Dwarf Model Atmospheres: Synthetic Spectra for Super Soft SourcesAug 31 2011The T\"ubingen NLTE Model-Atmosphere Package (TMAP) calculates fully metal-line blanketed white dwarf model atmospheres and spectral energy distributions (SEDs) at a high level of sophistication. Such SEDs are easily accessible via the German Astrophysical ... More
A grid of synthetic ionizing spectra for very hot compact stars from NLTE model atmospheresMar 20 2003The precise analysis of properties of planetary nebulae is strongly dependent on good models for the stellar ionizing spectrum. Observations in the UV - X-ray wavelength range as well as NLTE model atmosphere calculations of spectra of their exciting ... More
Branes in SupergroupsAug 13 2009In this thesis we initiate a systematic study of branes in Wess-Zumino-Novikov-Witten models with Lie supergroup target space. We start by showing that a branes' worldvolume is a twisted superconjugacy class and construct the action of the boundary WZNW ... More
The Supernovae Associated with Gamma-Ray BurstsOct 27 2004Supernovae (SNe) were long suspected as possible progenitors of gamma-ray bursts (GRBs). The arguments relied on circumstantial evidence. Several recent GRBs, notably GRB 030329, have provided direct, spectroscopic evidence that SNe and GRBs are related. ... More
Towards a Complexity-through-Realisability TheoryFeb 04 2015Jul 02 2015We explain how recent developments in the fields of realisability models for linear logic -- or geometry of interaction -- and implicit computational complexity can lead to a new approach of implicit computational complexity. This semantic-based approach ... More
Homological eigenvalues of mapping classes and torsion homology growth for fibered 3--manifoldsMay 01 2012Oct 02 2015Let S be an orientable surface with negative Euler characteristic, let \psi\in\Mod(S) be a mapping class of S, and let T_{\psi} be the mapping torus of \psi. We study the action of lifts of \psi on the homology of finite covers of S via the torsion homology ... More
E6Tensors: A Mathematica Package for E6 TensorsMay 19 2016We present the Mathematica package E6Tensors, a tool for explicit tensor calculations in E6 gauge theories. In addition to matrix expressions for the group generators of E6, it provides structure constants, various higher rank tensors and expressions ... More
A new property of the Alexander polynomialMar 10 2006Jun 21 2006This paper has been withdrawn because the result turns out to be trivial.
Towards a Mori theory on compact Kaehler threefolds, IIIFeb 26 1999We prove abundance for a minimal Kaehler threefold which is not both simple and non-Kummer. Recall that a variety is simple if there is no compact subvariety of positive dimension through a sufficiently general point . Furthermore we prove that a smooth ... More
Poisson Structure Induced Field Theories and Models of 1+1 Dimensional GravityNov 28 2000PhD thesis TU-Vienna, May 1994. Table of Contents: 1. Introduction, 2. Poisson Structure Induced Two Dimensional Field Theories, 3. Models of Gravity in 1+1 Dimensions
A Sufficient Condition for Partial Ensemble Controllability of Bilinear Schrödinger Equations with Bounded Coupling TermsMar 01 2013Mar 07 2013This note presents a sufficient condition for partial approximate ensemble controllability of a set of bilinear conservative quantum systems in an infinite dimensional Hilbert space. The proof relies on classical geometric and averaging control techniques ... More
Models for the n-Swiss Cheese operadsJun 23 2015We describe combinatorial Hopf (co-)operadic models for the Swiss Cheese operads built from Feynman diagrams. This extends previous work of Kontsevich and Lambrechts-Voli\'c for the little disks operads.
The oriented graph complexesAug 19 2013Aug 21 2013Oriented graph complexes, in which graphs are not allowed to have oriented cycles, govern for example the quantization of Lie bialgebras and infinite dimensional deformation quantization. It is shown that the oriented graph complex GC^or_n is quasi-isomorphic ... More
Parshin's conjecture revisitedJan 23 2007May 21 2008We show that Pashin's conjecture on the vanishing of rational higher K-groups of smooth, projective varieties over finite fields can be thought of as a combination of three weaker conjectures.
The integration of systems of linear PDEs using conservation laws of syzygiesJan 28 2003A new integration technique is presented for systems of linear partial differential equations (PDEs) for which syzygies can be formulated that obey conservation laws. These syzygies come for free as a by-product of the differential Groebner Basis computation. ... More
A comparison of four approaches to the calculation of conservation lawsJan 25 2003Feb 01 2003The paper compares computational aspects of four approaches to compute conservation laws of single differential equations (DEs) or systems of them, ODEs and PDEs. The only restriction, required by two of the four corresponding computer algebra programs, ... More
Extremal Radii, Diameter, and Minimum Width in Generalized Minkowski SpacesNov 05 2014Apr 13 2015We discuss the notions of circumradius, inradius, diameter, and minimum width in generalized Minkowski spaces (that is, with respect to gauges), i.e., we measure the "size" of a given convex set in a finite-dimensional real vector space with respect to ... More
Inclusive Decays of Heavy FlavoursMar 08 1995Recent progress in the theoretical description of inclusive heavy flavour decays is reviewed. After an outline of the theoretical methods applications to total decay rates and semileptonic decay spectra are presented.
Higher Order $1/m$ Corrections at Zero RecoilMar 09 1994The general structure of the $1/m$ corrections at zero recoil is studied. The relevant matrix elements are forward matrix elements of local higher dimensional operators and their time ordered products with higher order terms from the Lagrangian. These ... More
Global Structures on CR Manifolds via Nash Blow-upsSep 14 1999May 23 2000A generic compact real codimension two submanifold X of C^(n+2) will have a CR structure at all but a finite number of points (failing at the complex jump points J). The main theorem of this paper gives a method of extending the CR structure on the non-jump ... More
Exotic Quarkonium Spectroscopy: X(3872), Z_b(10610), and Z_b(10650) in Non-Relativistic Effective TheoryJan 07 2014This talk summarizes recent developments in quarkonium spectroscopy. I comment on the relation between the Z_b(10610) and Z_b(10650) and recently observed Z_c(3900) and Z_c(4025) states. Then I discuss a number of calculations using non-relativistic effective ... More
Recent Developments in Heavy Quark and Quarkonium ProductionDec 17 2003Dec 19 2003Recent measurements of J/psi production in e^+ e^- colliders pose a challenge to the NRQCD factorization theorem for quarkonium production. Discrepancies between leading order calculations of color-octet contributions and the momentum distribution of ... More
Focus on the Physics of CancerMay 16 2015Despite the spectacular achievements of molecular biology in the second half of the twentieth century and the crucial advances it permitted in cancer research, the fight against cancer has brought some disillusions. It is nowadays more and more apparent ... More
Wikipedia Tools for Google SpreadsheetsFeb 08 2016In this paper, we introduce the Wikipedia Tools for Google Spreadsheets. Google Spreadsheets is part of a free, Web-based software office suite offered by Google within its Google Docs service. It allows users to create and edit spreadsheets online, while ... More
Training recurrent neural networks with sparse, delayed rewards for flexible decision tasksJul 31 2015Dec 08 2015Recurrent neural networks in the chaotic regime exhibit complex dynamics reminiscent of high-level cortical activity during behavioral tasks. However, existing training methods for such networks are either biologically implausible, or require a real-time ... More
Density Functional Theory with Spatial-Symmetry Breaking and Configuration MixingJan 04 2013Feb 04 2013This article generalizes the notion of the local density of a many-body system to introduce collective coordinates as explicit degrees of freedom. It is shown that the energy of the system can be expressed as a functional of this object. The latter can ... More
Infinity-Inner-Products on A-Infinity-AlgebrasAug 03 2001Jan 22 2002In this paper the Hochschild-cochain-complex of an A-infinity-algebra A with values in an A-infinity-bimodule M over A and maps between them is defined. Then, an infinity-inner-product on A is defined to be an A-infinity-bimodule-map between A and its ... More
Chapman-Enskog expansion for the Vicsek model of self-propelled particlesMay 12 2016Aug 03 2016Using the standard Vicsek model, I show how the macroscopic transport equations can be systematically derived from microscopic collision rules. The approach starts with the exact evolution equation for the N-particle probability distribution, and after ... More
Towards a quantitative kinetic theory of polar active matterJan 31 2014Mar 26 2014A recent kinetic approach for Vicsek-like models of active particles is reviewed. The theory is based on an exact Chapman-Kolmogorov equation in phase space. It can handle discrete time dynamics and "exotic" multi-particle interactions. A nonlocal mean-field ... More
Transport coefficients of multi-particle collision algorithms with velocity-dependent collision rulesApr 15 2008Detailed calculations of the transport coefficients of a recently introduced particle-based model for fluid dynamics with a non-ideal equation of state are presented. Excluded volume interactions are modeled by means of biased stochastic multiparticle ... More
Geodesic rigidity of conformal connections on surfacesOct 30 2014May 09 2015We show that a conformal connection on a closed oriented surface $\Sigma$ of negative Euler characteristic preserves precisely one conformal structure and is furthermore uniquely determined by its unparametrised geodesics. As a corollary it follows that ... More
Lattice baryons in the 1/N expansionMay 01 2012Results are presented for hadron spectroscopy with gauge groups SU(N) with N=3, 5, 7. Calculations use the quenched approximation. Lattice spacings are matched using the static potential. Meson spectra show independence on N and vacuum-to-hadron matrix ... More
Kaon B-parameter using Overlap FermionsAug 26 2002I present first results from an in-progress calculation of B_K in quenched approximation using overlap fermions. My particular implementation of the overlap uses a kernel with nearest and next-nearest neighbor interactions and HYP-blocked gauge connections. ... More
Understanding chiral symmetry breaking with the overlap actionOct 02 2001A chiral fermion action allows one to do very clean studies of chiral symmetry breaking in QCD. I will briefly describe how to compute with the overlap action (relatively) cheaply, and then turn to physics: Low modes of the Dirac operator show a ``lumped'' ... More
A variant approach to the overlap actionJul 28 2000I describe an implementation of the overlap action, which is built from an action which is itself an approximate overlap action. It appears to be about a factor of 15-20 less expensive to use, than the usual overlap action with the Wilson fermion action ... More
Lattice studies of QCD-like theories with many fermionic degrees of freedomOct 22 2010I give an elementary introduction to the study of gauge theories coupled to fermions with many degrees of freedom. Besides their intrinsic interest, these theories are candidates for nonperturbative extensions of the Higgs sector of the Standard Model. ... More
The structure of E10 at higher A9 levels - a first algorithmic approachApr 28 2005The conjecture of a hidden $E_{10}$ symmetry of M-theory is supported by the close connection between the dynamics of D=11 supergravity near a spacelike singularity and a truncation of an one-dimensional $\sigma$-model with $E_{10}$ symmetry where all ... More
Measure What Should be Measured: Progress and Challenges in Compressive SensingOct 25 2012Is compressive sensing overrated? Or can it live up to our expectations? What will come after compressive sensing and sparsity? And what has Galileo Galilei got to do with it? Compressive sensing has taken the signal processing community by storm. A large ... More
KPP reaction-diffusion equations with a non-linear loss inside a cylinderApr 17 2010We consider in this paper a reaction-diffusion system in presence of a flow and under a KPP hypothesis. While the case of a single-equation has been extensively studied since the pioneering Kolmogorov-Petrovski-Piskunov paper, the study of the corresponding ... More
Low Mach number flows, and combustionNov 07 2005We prove uniform existence results for the full Navier-Stokes equations for time intervals which are independent of the Mach number, the Reynolds number and the P\'eclet number. We consider general equations of state and we give an application for the ... More
Tomography of one and two qubit states and factorisation of the Wigner distribution in prime power dimensionsApr 17 2006We study different techniques that allow us to gain complete knowledge about an unknown quantum state, e.g. to perform full tomography of this state. We focus on two apparently simple cases, full tomography of one and two qubit systems. We analyze and ... More
Bell states, mutually unbiased bases and the Mean King's problemJan 08 2004Jun 27 2005When the state of a quantum system belongs to a N-dimensional Hilbert space, with N the power of a prime number, it is possible to associate to the system a finite field (Galois field) with N elements. In this paper, we introduce generalized Bell states ... More
Phases and phase transitions in disordered quantum systemsJan 31 2013These lecture notes give a pedagogical introduction to phase transitions in disordered quantum systems and to the exotic Griffiths phases induced in their vicinity. We first review some fundamental concepts in the physics of phase transitions. We then ... More
Broadening of a nonequilibrium phase transition by extended structural defectsFeb 24 2004Sep 01 2004We study the effects of quenched extended impurities on nonequilibrium phase transitions in the directed percolation universality class. We show that these impurities have a dramatic effect: they completely destroy the sharp phase transition by smearing. ... More
Smearing of the phase transition in Ising systems with planar defectsMar 27 2003Aug 06 2003We show that phase transitions in Ising systems with planar defects, i.e., disorder perfectly correlated in two dimensions are destroyed by smearing. This is caused by effects similar to but stronger than the Griffiths phenomena: Exponentially rare spatial ... More