Results for "Nicole Hiller"

total 1420took 0.21s
Adaptive and Safe Bayesian Optimization in High Dimensions via One-Dimensional SubspacesFeb 08 2019May 28 2019Bayesian optimization is known to be difficult to scale to high dimensions, because the acquisition step requires solving a non-convex optimization problem in the same search space. In order to scale the method and keep its benefits, we propose an algorithm ... More
Note: Nanomechanical characterization of soft materials using a micro-machined nanoforce transducer with an FIB-made pyramidal tipJan 24 2019The quantitative nanomechanical characterization of soft materials using the nanoindentation technique requires further improvements in the performances of instruments, including their force resolution in particular. A micro-machined silicon nanoforce ... More
Improved QCD perturbative contributions and power corrections in radiative and semileptonic rare B decaysSep 23 1998We calculate the leading power corrections to the decay rates, distributions and hadronic spectral moments in rare inclusive \bxsll decays in the standard model, using heavy quark expansion (HQE) in $(1/m_b)$ and a phenomenological model implementing ... More
Testing factorizationNov 19 2001We briefly review the status of factorization in $b$-decays. We discuss several experimental tests of its nature and stress their importance. We show that decays into mesons which have small decay constants or spin greater than one (`designer mesons') ... More
First hint of non-standard CP violation from B --> Phi K_S decayJul 30 2002Oct 10 2002We comment on the implications of the recently measured CP asymmetry in B --> Phi K_S decay. The data disfavor the Standard Model at 2.7 sigma and -if the trend persists in the future with higher statistics - require the existence of CP violation beyond ... More
$b \to s \ell^+ \ell^-$ decays in and beyond the Standard ModelAug 09 2000We briefly review the status of rare radiative and semileptonic $b \to s (\gamma, \ell^+ \ell^-)$, ($\ell=e,\mu$) decays. We discuss possible signatures of new physics in these modes and emphazise the role of the exclusive channels. In particular, measurements ... More
B -> K(*) l+ l- @ Low Recoil and Physics ImplicationsMay 28 2013This talk covers recent theoretical progress in exclusive semileptonic rare B-decays at low hadronic recoil. The efficient parametric suppression of the 1/mb corrections in this region provides opportunities to probe the Standard Model and beyond at precision ... More
Flavor violation in SUSYMay 04 2009I review recent opportunities from flavor for b-physics and collider searches.
b-physics signals of the lightest CP-odd Higgs in the NMSSM at large tan betaApr 24 2004Jun 17 2004We investigate the low energy phenomenology of the lighter pseudoscalar $A_1^0$ in the NMSSM. The $A_1^0$ mass can naturally be small due to a global $U(1)_R$ symmetry of the Higgs potential, which is only broken by trilinear soft terms. The $A_1^0$ mass ... More
The Pheno-analysis of B-> K(*) mu^+ mu^- decays in 2011 plusJun 08 2011We report on recent developments in the phenomenology of exclusive b -> s mu^+ mu^- decays in testing the standard model and explore its borders: the benefits of the region of large dimuon invariant masses and the exploitation of the angular distributions. ... More
$B \to K^* \ell \ell$ Standard Model contributions -- Zooming in on high $q^2$Jun 05 2016To further precision studies with $B \to K^{(*)} \ell \ell$ decays in the high-$q^2$ window uncertainties related to the operator product expansion (OPE) need to be scrutinized. How well can the OPE describe $B \to K^* (\to K \pi) \ell \ell$ angular distributions ... More
Physics reach of rare b-decaysJul 09 2002I discuss the theoretical and empirical status of $b \to s \gamma$, $b \to s \ell^+ \ell^-$ decays, as well as their future prospects. I emphasize those observables in rare $b$-decays which can potentially establish new physics and distinguish between ... More
Phenomenology of New PhysicsAug 18 2003Sep 10 2003I review the phenomenology of new physics in low energy processes using the notion of minimal flavor violation (vs. non-minimal flavor violation). I compare the predictions of beyond-the-standard models and show that among certain observables in rare ... More
From self-organization in relativistic electron bunches to coherent synchrotron light: observation using a photonic time-stretch digitizerFeb 16 2019In recent and future synchrotron radiation facilities, relativistic electron bunches with increasingly high charge density are needed for producing brilliant light at various wavelengths, from X-rays to terahertz. In such conditions, interaction of electrons ... More
Adaptive and Safe Bayesian Optimization in High Dimensions via One-Dimensional SubspacesFeb 08 2019Bayesian optimization is known to be difficult to scale to high dimensions, because the acquisition step requires solving a non-convex optimization problem in the same search space. In order to scale the method and keep its benefits, we propose an algorithm ... More
The CP-conserving contribution to the transverse muon polarization in K+ -> mu+ nu gammaMar 08 1999We present a detailed estimate of the transverse muon polarization (P_T) due to electromagnetic final-state interactions in the decay $K^+ \to \mu^+ \nu \gamma$. This CP-conserving effect represents the dominant contribution to P_T within the Standard ... More
Nonperturbative solution of Yukawa theory and gauge theoriesJul 20 2004Recent progress in the nonperturbative solution of (3+1)-dimensional Yukawa theory and quantum electrodynamics (QED) and (1+1)-dimensional super Yang-Mills (SYM) theory will be summarized. The work on Yukawa theory has been extended to include two-boson ... More
Nonperturbative light-front methodsOct 10 2003Two methods for the nonperturbative solution of field-theoretic bound-state problems, based on light-front coordinates, are briefly reviewed. One uses Pauli-Villars regularization and the other supersymmetry. Applications to Yukawa theory and super Yang-Mills ... More
Methods for the nonperturbative approximation of form factors and scattering amplitudesJul 26 2000Methods are described for the nonperturbative calculation of wave functions and scattering amplitudes in light-cone quantization. Form factors are computed from the boost-invariant wave functions, which appear as coefficients in a Fock-state expansion ... More
Dynamic Simulation of Soft Heterogeneous ObjectsDec 12 2012This paper describes a 2D and 3D simulation engine that quantitatively models the statics, dynamics, and non-linear deformation of heterogeneous soft bodies in a computationally efficient manner. There is a large body of work simulating compliant mechanisms. ... More
A nonperturbative coupled-cluster method for quantum field theoriesAug 31 2012The nonperturbative Hamiltonian eigenvalue problem for bound states of a quantum field theory is formulated in terms of Dirac's light-front coordinates and then approximated by the exponential-operator technique of the many-body coupled-cluster method. ... More
A nonperturbative light-front coupled-cluster methodAug 30 2012The nonperturbative Hamiltonian eigenvalue problem for bound states of a quantum field theory is formulated in terms of Dirac's light-front coordinates and then approximated by the exponential-operator technique of the many-body coupled-cluster method. ... More
Supersymmetric Two-Dimensional QCD at Finite TemperatureAug 04 2006Light-cone coordinates and supersymmetric discrete light-cone quantization are used to analyze the thermodynamics of two-dimensional supersymmetric quantum chromodynamics with a Chern-Simons term in the large-N_c approximation. This requires estimation ... More
Calculations with DLCQJul 26 2000The method of discrete light-cone quantization (DLCQ) and useful refinements are summarized. Applications to various field theories are reviewed.
Pauli-Villars regularization and discrete light-cone quantization in Yukawa theoryFeb 21 2000The techniques of Pauli-Villars regularization and discrete light-cone quantization are combined to analyze Yukawa theory in a single-fermion truncation. A special form of the Lanczos algorithm is constructed for diagonalization of the indefinite-metric ... More
A Theoretical Reappraisal of Branching Ratios and CP Asymmetries in the Decays $B \to (X_d,X_s) \ell^+ \ell^-$ and Determination of the CKM ParametersDec 07 1998We present a theoretical reappraisal of the branching ratios and CP asymmetries for the decays $ B \to X_q \ell^+ \ell^-$, with $q=d,s$, taking into account current theoretical uncertainties in the description of the inclusive decay amplitudes from the ... More
Solving the strong CP problem with supersymmetryMay 24 2001Jun 24 2001We propose a new solution to the strong CP problem based on supersymmetric non-renormalization theorems. CP is broken spontaneously and it's breaking is communicated to the MSSM by radiative corrections. The strong CP phase is protected by a susy non-renormalization ... More
New ways to explore factorization in b decaysMay 18 2001Jul 09 2001We propose to study factorization breaking effects in exclusive b decays where they are strongly enhanced over the factorizing contributions. This can be done by selecting final-state mesons with a small decay constant or with spin greater than one. We ... More
Measuring Flavor Mixing with Minimal Flavor Violation at the LHCFeb 07 2008Aug 25 2008The mixing between third and second (or first) generation squarks is very small in supersymmetric models with minimal flavor violation such as gauge-, anomaly- or gaugino-mediation. An opportunity to measure this mixing will arise if the lightest stop ... More
Perturbative QCD- and Power-Corrected Hadron Spectra and Spectral Moments in the Decay $B \to X_s \ell^+ \ell^-$Mar 23 1998Mar 27 1998We compute the leading order (in $\alpha_s$) perturbative QCD and power ($1/m_b^2)$ corrections to the hadronic invariant mass and hadron energy spectra in the decay $B \to X_s \ell^+ \ell^-$ in standard model. This is done both by using the heavy quark ... More
Probing for New Physics in Polarized $Λ_b$ decays at the ZAug 08 2001Jan 29 2002Polarized $\Lambda_b \to \Lambda \gamma$ decays at the Z pole are shown to be well suited for probing a large variety of New Physics effects. A new observable is proposed, the angular asymmetry between the $\Lambda_b$ spin and photon momentum, which is ... More
$R_K$ and future $b \to s \ell \ell$ BSM opportunitiesAug 07 2014Flavor changing neutral current $|\Delta B|=|\Delta S|=1$ processes are sensitive to possible new physics at the electroweak scale and beyond, providing detailed information about flavor, chirality and Lorentz structure. Recently the LHCb collaboration ... More
More Model-Independent Analysis of b->s ProcessesOct 17 2003Jan 09 2004We study model-independently the implications of non-standard scalar and pseudoscalar interactions for the decays b ->s gamma, b -> s g, b -> s l^+l^- (l=e,mu) and B_s -> mu^+ mu^-. We find sizeable renormalization effects from scalar and pseudoscalar ... More
Flavorful hybrid anomaly-gravity mediationJan 27 2011May 26 2011We consider supersymmetric models where anomaly and gravity mediation give comparable contributions to the soft terms and discuss how this can be realized in a five-dimensional brane world. The gaugino mass pattern of anomaly mediation is preserved in ... More
A short note on the order of the Zhang-Liu matrices over arbitrary fieldsFeb 04 2017We give necessary and sufficient conditions for the Zhang-Liu matrices to be diagonalizable over arbitrary fields and provide the eigen-decomposition when it is possible. We use this result to calculate the order of these matrices over any arbitrary field. ... More
Four-Dimensional Algebraic ToriNov 01 2015Nov 03 2015The study of the birational properties of algebraic $k$ tori began in the sixties and seventies with work of Voskresenkii, Endo, Miyata, Colliot-Thelene and Sansuc. There was particular interest in determining the rationality of a given algebraic $k$ ... More
The $abc$-Conjecture implies uniform bounds on dynamical Zsigmondy setsNov 04 2017We prove that the $abc$-Conjecture implies upper bounds on Zsigmondy sets that are uniform over families of unicritical polynomials over number fields. As an application, we use the $abc$-Conjecture to prove that there exist uniform bounds on the index ... More
Reducing training time by efficient localized kernel regressionJul 11 2017Feb 24 2019We study generalization properties of kernel regularized least squares regression based on a partitioning approach. We show that optimal rates of convergence are preserved if the number of local sets grows sufficiently slowly with the sample size. Moreover, ... More
An Ehrenfeucht-Fraisse Game Approach to Collapse Results in Database TheoryDec 20 2002We present a new Ehrenfeucht-Fraisse game approach to collapse results in database theory and we show that, in principle, this approach suffices to prove every natural generic collapse result. Following this approach we can deal with certain infinite ... More
Sur les espaces de modules des fibres vectoriels de rang deux sur des hypersurfaces de P^3Jan 08 1996Mar 15 1996Soit $X$ une hypersurface lisse de degr\'e $\delta \geq 4$ dans $\pp ^3$ telle que $Pic(X)=Z$. On d\'esigne par $M_X(c_2)$ l'espace de modules des fibr\'es vectoriels sur $X$ de classes de Chern $c_1 = 0$ et $c_2$, semi-stables par rapport au diviseur ... More
Coisotropic Subalgebras of Complex Semisimple Lie BialgebrasSep 03 2014In his paper "A Construction for Coisotropic Subalgebras of Lie Bialgebras", Marco Zambon gave a way to use a long root of a complex semisimple Lie biaglebra $\mathfrak{g}$ to construct a coisotropic subalgebra of $\mathfrak{g}$. In this paper, we generalize ... More
On the Peaking Phenomenon of the Lasso in Model SelectionApr 28 2009I briefly report on some unexpected results that I obtained when optimizing the model parameters of the Lasso. In simulations with varying observations-to-variables ratio n=p, I typically observe a strong peak in the test error curve at the transition ... More
Status of EXO-200Sep 09 2009EXO-200 is the first phase of the Enriched Xenon Observatory (EXO) experiment, which searches for neutrinoless double beta decay in 136Xe to measure the mass and probe the Majorana nature of the neutrino. EXO-200 consists of 200 kg of liquid Xe enriched ... More
A lower bound on the canonical height for polynomialsSep 23 2017We prove a lower bound on the canonical height associated to polynomials over number fields evaluated at points with infinite forward orbit. The lower bound depends only on the degree of the polynomial, the degree of the number field, and the number of ... More
Optical Spectroscopy as a Probe of Gaps and Kinetic Electronic Energy in p- and n-type cupratesOct 11 2006The real part of the optical in-plane conductivity of p-- and n--type cuprates thin films at various doping levels was deduced from highly accurate reflectivity measurements. We present here a comprehensive set of optical spectral weight data as a function ... More
Lower Bounds for Multi-Pass Processing of Multiple Data StreamsFeb 10 2009This paper gives a brief overview of computation models for data stream processing, and it introduces a new model for multi-pass processing of multiple streams, the so-called mp2s-automata. Two algorithms for solving the set disjointness problem wi th ... More
Support varieties and the Hochschild cohomology ring modulo nilpotenceNov 27 2008Dec 05 2008This is a survey paper based on my talks at the 41st Symposium on Ring Theory and Representation Theory, held in Shizuoka University, Japan in September 2008, and will appear in the conference proceedings. The paper begins with a brief introduction to ... More
Diagnosing lepton-nonuniversality in $b \to s \ell \ell$Nov 18 2014Feb 08 2015Ratios of branching fractions of semileptonic B decays, $(B \to H \mu \mu)$ over $(B \to H ee)$ with $H=K, K^*,X_s, K_0(1430), \phi, \ldots$ are sensitive probes of lepton universality. In the Standard Model, the underlying flavor changing neutral current ... More
Extracting $B \to K^*$ Form Factors from DataApr 19 2012We extract ratios of $B \to K^*$ form factors at low hadronic recoil from recent data on $B \to K^* \mu^+ \mu^-$ decays in a model-independent way. The presented method will improve in the future with further (angular) studies in semileptonic rare B-decays ... More
Semileptonic Form-factors from B-> K* gamma Decays in the Large Energy LimitNov 21 2000Making use of the measurement of the $B\to K^*\gamma$ branching ratio together with the relations following from the limit of high recoil energy, we obtain stringent constraints on the values of the form-factors entering in heavy-to-light $B\to V\ell\ell'$ ... More
Implications of Non-Standard CP Violation in Hadronic $B$-DecaysJul 21 2003Jul 29 2004We investigate a class of models for new physics which could produce a large difference in sin 2 beta between B0-> J/\psi K(S) and the ``pure penguin'' mode B0-> phi K(S). In such models, the dominant effect is through a Z-penguin and therefore a pattern ... More
Yet another way to measure $γ$May 21 2001Sep 17 2001We show that the CKM phase $2 \beta+\gamma$ can be extracted from measurement of the time dependent rates in the decays $\bar{B}^0 \to D^{(*)\pm} M^\mp$ and $B^0 \to D^{(*)\pm} M^\mp$, where $M=a_0$, $\pi(1300)$, $b_1$, $a_2$, $\pi_2$, $\rho_3$. These ... More
Local models for ramified unitary groupsFeb 03 2003In this article, we study local models associated to certain Shimura varieties. In particular, we present a resoultion of their singularities. As a consequence, we are able to determine the alternating semisimple trace of the geometric Frobenius on the ... More
On the regularity of critical points for O'Hara's knot energies: From smoothness to analyticityApr 30 2019We prove the analyticity of smooth critical points for O'Hara's knot energies $\mathcal{E}^{\alpha,p}$, with $p=1$ and $2<\alpha< 3$, subject to a fixed length constraint. This implies, together with the main result in \cite{BR13}, that bounded energy ... More
Measurements of Proton Structure Functions, alpha_s and Parton Distribution Functions at HERAMay 30 2003Jun 02 2003The measurement and QCD analysis of neutral and charged current cross sections at HERA are presented. For the kinematic range of four-momentum transfer Q^2 between approx. 1 GeV^2 and 30000 GeV^2 and Bjorken x between 0.0013 and 0.65 the data are compared ... More
Boosting for Functional DataMay 30 2006We deal with the task of supervised learning if the data is of functional type. The crucial point is the choice of the appropriate fitting method (learner). Boosting is a stepwise technique that combines learners in such a way that the composite learner ... More
(A)symmetries of weak decays at and near the kinematic endpointDec 06 2013Mar 05 2014At the kinematic endpoint of zero recoil physical momenta are parallel which leads to symmetries in the decay distributions. We implement this observation for decays of the type $A \to (B_1 B_2) C$ by extending the helicity formalism to include an unphysical ... More
Strong-weak CP hierarchy from non-renormalization theoremsJan 27 2002We point out that the hierarchy between the measured values of the CKM phase and the strong CP phase has a natural origin in supersymmetry with spontaneous CP violation and low energy supersymmetry breaking. The underlying reason is simple and elegant: ... More
Perturbative QCD and Power Corrected Hadron Spectra and Spectral Moments in the Decays $B \to X_s \ell^+ \ell^-$Dec 18 1998Leading order (in $\alpha_s$) perturbative QCD and power ($1/m_b^2)$ corrections to the hadronic invariant mass and hadron energy spectra in the decay $B \to X_s \ell^+ \ell^-$ are reviewed in the standard model using the heavy quark expansion technique ... More
Phenomenological Profiles of the Inclusive Hadron Spectra in the Decay $B \to X_s \ell^+ \ell^-$Jul 19 1998Hadron spectra and hadronic moments in the decay $B \to X_s \ell^+ \ell^-$ are calculated taking into account both the short-distance and long-distance contributions in the decay amplitude using a Fermi motion (FM) model to incorporate the $B$-meson wave-function ... More
Hadron Spectra and Spectral Moments in the Decay B \to X_s \ell^+ \ell^- using HQETMar 20 1998We compute the leading order (in alpha_s) perturbative QCD and power (1/m_b^2) corrections to the hadronic invariant mass and hadron energy spectra in the decay B \to X_s \ell^+ \ell^- in standard model using the heavy quark expansion technique (HQET). ... More
Dynamical uniform boundedness and the $abc$-conjectureJan 14 2019We address the Uniform Boundedness Conjecture of Morton and Silverman in the case of unicritical polynomials, assuming a generalization of the $abc$-conjecture. For unicritical polynomials of degree at least five, we require only the standard $abc$-conjecture. ... More
Arithmetic, First-Order Logic, and Counting QuantifiersNov 19 2002This paper gives a thorough overview of what is known about first-order logic with counting quantifiers and with arithmetic predicates. As a main theorem we show that Presburger arithmetic is closed under unary counting quantifiers. Precisely, this means ... More
Four-Dimensional Algebraic ToriNov 01 2015Aug 04 2017The study of the birational properties of algebraic $k$-tori began in the sixties and seventies with work of Voskresenkii, Endo, Miyata, Colliot-Th\'el\`ene and Sansuc. There was particular interest in determining the rationality of a given algebraic ... More
Adaptivity for Regularized Kernel Methods by Lepskii's PrincipleApr 15 2018We address the problem of {\it adaptivity} in the framework of reproducing kernel Hilbert space (RKHS) regression. More precisely, we analyze estimators arising from a linear regularization scheme $g_\lam$. In practical applications, an important task ... More
Leading logarithmic QCD corrections to the B_s --> γγdecay rate including long-distance effects through B_s --> φγ--> γ γApr 23 1997Feb 02 1998We present leading logarithmic QCD corrections to the decay B_s --> \gamma\gamma in the Standard Model. Further, the form factor F_{1}(0) of B_s --> \phi\gamma is calculated in the framework of QCD sum rules and found to be in agreement with the result ... More
Predictions for $B \to K γγ$ decaysNov 26 2004Oct 15 2011We present a phenomenological study of the rare double radiative decay $B\to K \gamma\gamma$ in the Standard Model (SM) and beyond. Using the operator product expansion (OPE) technique, we estimate the short-distance (SD) contribution to the decay amplitude ... More
Phenomenological study of the double radiative decay $B ->Kγγ$Nov 29 2005Using the operator product expansion (OPE) technique, we study the rare double radiative decay $B\to K \gamma\gamma$ in the Standard Model (SM) and beyond. We estimate the short-distance (SD) contribution to the decay amplitude in a region of the phase ... More
Flavor & new physics opportunities with rare charm decays into leptonsOct 01 2015Mar 22 2016Updated standard model predictions for $D_{(s)} \to P l^+ l^-$, $l=e,\mu$, $P=\pi,K$ and inclusive decays are presented. Model-independent constraints on $|\Delta C|=|\Delta U|=1$ Wilson coefficients are worked out. New physics (NP) opportunities arise ... More
Optimal Dividend Payout Model with Risk Sensitive PreferencesMay 31 2016We consider a discrete-time dividend payout problem with risk sensitive shareholders. It is assumed that they are equipped with a risk aversion coefficient and construct their discounted payoff with the help of the exponential premium principle. This ... More
First-Order Logic with Counting: At Least, Weak Hanf Normal Forms Always Exist and Can Be Computed!Mar 03 2017We introduce the logic FOCN(P) which extends first-order logic by counting and by numerical predicates from a set P, and which can be viewed as a natural generalisation of various counting logics that have been studied in the literature. We obtain a locality ... More
Kernel regression, minimax rates and effective dimensionality: beyond the regular caseNov 12 2016We investigate if kernel regularization methods can achieve minimax convergence rates over a source condition regularity assumption for the target function. These questions have been considered in past literature, but only under specific assumptions about ... More
Dynamical Galois groups of trinomials and Odoni's conjectureSep 12 2016Oct 13 2016We prove Odoni's conjecture in all prime degrees; namely, we prove that for every positive prime $p$, there exists a degree $p$ polynomial $\varphi\in\mathbb{Z}[x]$ with surjective arboreal Galois representation. We also show that Vojta's conjecture implies ... More
Towards an Understanding of GRB Prompt EmissionFeb 07 2002We discuss the prompt emission of Gamma-Ray Bursts in different spectral energy bands. First, we suggest that a three-part synchrotron emission model is a good description of the ~20 keV - 1 MeV gamma-ray emission of GRBs. We show that this model provides ... More
Mirror matter and heavy singlet neutrino oscillations in the early universeMar 09 2000We investigate the mixing of heavy gauge singlet neutrinos in a mirror matter model employing the seesaw mechanism. The parameter constraints that must be satisfied to prevent the overproduction of mirror matter in the early universe are deduced. We find ... More
Piecewise Empirical LikelihoodApr 21 2016Dec 14 2017Non-parametric methods avoid the problem of having to specify a particular data generating mechanism, but can be computationally intensive, reducing their accessibility for large data problems. Empirical likelihood, a non-parametric approach to the likelihood ... More
Partially Observable Risk-Sensitive Markov Decision ProcessesApr 14 2015Nov 29 2016We consider the problem of minimizing a certainty equivalent of the total or discounted cost over a finite and an infinite time horizon which is generated by a Partially Observable Markov Decision Process (POMDP). The certainty equivalent is defined by ... More
A note on monadic datalog on unranked treesOct 04 2013In the article 'Recursive queries on trees and data trees' (ICDT'13), Abiteboul et al., asked whether the containment problem for monadic datalog over unordered unranked labeled trees using the child relation and the descendant relation is decidable. ... More
Revealing the Asymmetry of the Wind of the Variable Wolf-Rayet Star WR1 (HD4004) Through SpectropolarizationAug 27 2013In this paper, high quality spectropolarimetric observations of the Wolf-Rayet (WR) Star WR1 (HD4004) obtained with ESPaDOnS at CFHT are presented. All major emission lines present in the spectrum show depolarization in the relative Stokes parameters ... More
On the charge of nanograins in cold environments and Enceladus dustJun 10 2013In very-low energy plasmas, the size of nanograins is comparable to the distance (the so-called Landau length) at which the interaction energy of two electrons equals their thermal energy. In that case, the grain's polarization induced by approaching ... More
Modeling of macroscopic stresses in a dilute suspension of small weakly inertial particlesJul 30 2015In this paper we derive asymptotically the macroscopic bulk stress of a suspension of small inertial particles in an incompressible Newtonian fluid. We apply the general asymptotic framework to the special case of ellipsoidal particles and show the resulting ... More
Portfolio Optimization in Fractional and Rough Heston ModelsSep 27 2018May 16 2019We consider a fractional version of the Heston volatility model which is inspired by [16]. Within this model we treat portfolio optimization problems for power utility functions. Using a suitable representation of the fractional part, followed by a reasonable ... More
Improved Dynamic Graph ColoringApr 29 2019This paper studies the fundamental problem of graph coloring in fully dynamic graphs. Since the problem of computing an optimal coloring, or even approximating it to within $n^{1-\epsilon}$ for any $\epsilon > 0$, is NP-hard in static graphs, there is ... More
Galois groups over rational function fields and explicit Hilbert irreducibilityAug 15 2017Let $P\in\mathbb Q[t,x]$ be a polynomial in two variables with rational coefficients, and let $G$ be the Galois group of $P$ over the field $\mathbb Q(t)$. It follows from Hilbert's Irreducibility Theorem that for most rational numbers $c$ the specialized ... More
T=0 effective interaction in 14N and 10BNov 20 2007We have calculated the 1+ and 3+, T=0 states in 14N and 10B. In a neutron-proton RPA model these two nuclei are described by the same set of equations. We first show that a bare Minnesota interaction leads to too weak binding in bothnuclei. Furthermore ... More
Deformation or spherical symmetry in 10Be and the inversion of 1/2- - 1/2+ states in 11BeNov 20 2007For a core plus one neutron system like 11Be we have calculated the energies of the 1/2- and 1/2+ states assuming a deformation of the core deduced from the low energy 2+ state properties or taking into account the coupling of the neutron with this 2+ ... More
Measuring and hedging financial risks in dynamical worldMay 01 2003Financial markets have developed a lot of strategies to control risks induced by market fluctuations. Mathematics has emerged as the leading discipline to address fundamental questions in finance as asset pricing model and hedging strategies. History ... More
Zero-sum Risk-Sensitive Stochastic GamesApr 07 2016Jun 29 2016In this paper we consider two-person zero-sum risk-sensitive stochastic dynamic games with Borel state and action spaces and bounded reward. The term risk-sensitive refers to the fact that instead of the usual risk neutral optimization criterion we consider ... More
Equivariant Euler characteristics of discriminants of reflection groupsJan 16 2002Let G be a finite, complex reflection group and f its discriminant polynomial. The fibers of f admit commuting actions of G and a cyclic group. The virtual $G\times C_m$ character given by the Euler characteristic of the fiber is a refinement of the zeta ... More
Superspecial Abelian Varieties and the Eichler Basis Problem for Hilbert Modular FormsNov 02 2007Jun 17 2008Let $p$ be an unramified prime in a totally real field $L$ such that $h^+(L)=1$. Our main result shows that Hilbert modular newforms of parallel weight two for $\Gamma_0(p)$ can be constructed naturally, via classical theta series, from modules of isogenies ... More
Hochschild cohomology of socle deformations of a class of Koszul self-injective algebrasMay 18 2009Feb 23 2010We consider the socle deformations arising from formal deformations of a class of Koszul self-injective special biserial algebras which occur in the study of the Drinfeld double of the generalized Taft algebras. We show, for these deformations, that the ... More
Partially Observable Risk-Sensitive Markov Decision ProcessesApr 14 2015Oct 27 2015We consider the problem of minimizing a certainty equivalent of the total or discounted cost over a finite and an infinite time horizon which is generated by a Partially Observable Markov Decision Process (POMDP). The certainty equivalent is defined by ... More
Piecewise Empirical LikelihoodApr 21 2016Non-parametric methods avoid the problem of having to specify a particular data generating mechanism, but can be computationally intensive, reducing their accessibility for large data problems. Empirical likelihood, a non-parametric approach to the likelihood ... More
Risk Management with Tail Conditional Certainty EquivalentsFeb 19 2019Certainty Equivalent is a utility-based measure that performs as a measure in which investors are indifferent between this measure and investment that holds some uncertainty. Therefore, it plays an essential role in utility-based decision making. One ... More
PrivySense: $\underline{Pri}$ce $\underline{V}$olatilit$\underline{y}$ based $\underline{Sen}$timent$\underline{s}$ $\underline{E}$stimation from Financial News using Machine LearningDec 30 2017Feb 21 2018As machine learning ascends the peak of computer science zeitgeist, the usage and experimentation with sentiment analysis using various forms of textual data seems pervasive. The effect is especially pronounced in formulating securities trading strategies, ... More
Science with an ngVLA: Radio Emission from Short Gamma-ray Bursts in the Multi-Messenger EraSep 25 2017Oct 12 2018We investigate the expected radio emission from short GRBs, guided by the observed distributions of their afterglow parameters. Our motivation is to explore the radio signatures of the forward and reverse shock in a sGRB jet, as well as the off-axis jet ... More
Planck's blackbody radiation law: Presentation in different domains and determination of the related dimensional constantsJan 13 2009Nov 12 2009In this paper the Planck function is derived in the frequency domain using the method of oscillators. It is also presented in the wavelength domain and in the wave number domain. The latter is mainly used in spectroscopy for studying absorption and emission ... More
How Magnetic is the Neutrino?Jul 11 2007The existence of a neutrino magnetic moment implies contributions to the neutrino mass via radiative corrections. We derive model-independent "naturalness" upper bounds on the magnetic moments of Dirac and Majorana neutrinos, generated by physics above ... More
The equivariant Todd genus of a complete toric variety, with Danilov conditionOct 15 2006We write the equivariant Todd class of a general complete toric variety as an explicit combination of the orbit closures, the coefficients being analytic functions on the Lie algebra of the torus which satisfy Danilov's requirement.
On the locality of arb-invariant first-order formulas with modulo counting quantifiersNov 23 2016Dec 27 2016We study Gaifman locality and Hanf locality of an extension of first-order logic with modulo p counting quantifiers (FO+MOD_p, for short) with arbitrary numerical predicates. We require that the validity of formulas is independent of the particular interpretation ... More