Results for "Silas Alben"

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Optimal convection cooling flows in general geometriesJul 07 2016We generalize a recent method for computing optimal 2D convection cooling flows in a horizontal layer to a wide range of geometries, including those relevant for technological applications. We write the problem in a conformal pair of coordinates which ... More
Color scales that are effective in both color and grayscaleNov 15 2012We consider the problem of finding a color scale which performs well when converted to a grayscale. We assume that each color is converted to a shade of gray with the same intensity as the color. We also assume that the color scales have a linear variation ... More
Optimizing snake locomotion on an inclined planeOct 18 2013We develop a model to study the locomotion of snakes on an inclined plane. We determine numerically which snake motions are optimal for two retrograde traveling-wave body shapes---triangular and sinusoidal waves---across a wide range of frictional parameters ... More
Efficient sliding locomotion with isotropic frictionFeb 08 2019Snakes' bodies are covered in scales that make it easier to slide in some directions than in others. This frictional anisotropy allows for sliding locomotion with an undulatory gait, one of the most common for snakes. Isotropic friction is a simpler situation ... More
Collapse and folding of pressurized rings in two dimensionsDec 12 2008Hydrostatically pressurized circular rings confined to two dimensions (or cylinders constrained to have only z-independent deformations) undergo Euler type buckling when the outside pressure exceeds a critical value. We perform a stability analysis of ... More
Stability and scalability of piezoelectric flagsSep 22 2015We investigate the effect of piezoelectric (PZT) material on the flutter speed, vibration mode and frequency, and energy harvesting power and efficiency of a flexible flag in various fluids. We develop a fully coupled fluid-solid-electric model by combining ... More
Nuclear forces on the latticeDec 30 2009Recent studies by the NPLQCD collaboration of hadronic interactions using lattice QCD are reviewed, with an emphasis on a recent calculation of meson-baryon scattering lengths. Ongoing high-statistics calculations of baryon interactions are also reviewed. ... More
A finiteness theorem for weighted discriminants with mass formulasOct 15 2014We define the notion of a weighted discriminant and corresponding counting function for number fields, and what it means for these counting functions to have a mass formula for a set of primes. We prove that for $\Gamma$ an $\ell$-group, there are only ... More
Randomly Generated Subgroups of the Symmetric Group and Random Lifts of GraphsJul 05 2016Aug 02 2016Amit and Linial showed that a random lift of a graph with minimum degree $\delta\ge3$ is asymptotically almost surely $\delta$-connected, and mentioned the problem of estimating this probability as a function of the degree of the lift. We relate a randomly ... More
New approach to NN with perturbative pionsDec 29 2009The current status of effective field theory (EFT) descriptions of nucleon-nucleon (NN) interactions is briefly reviewed, and a new formulation of EFT which treats pion interactions perturbatively is presented. This approach differs from the Kaplan-Savage-Wise ... More
Stable Pentaquarks from Strange Chiral MultipletsAug 04 2004The assumption of strong diquark correlations in the QCD spectrum suggests flavor multiplets of hadrons that are degenerate in the chiral limit. Generally it would be unnatural for there to be degeneracy in the hadron spectrum that is not protected by ... More
Nucleon Masses and Magnetic Moments in a Finite VolumeMar 12 2004Jun 09 2004We compute finite-size corrections to nucleon masses and magnetic moments in a periodic, spatial box of size L, both in QCD and in partially-quenched QCD.
Elusive Neutrons from Nuclei in Effective Field TheorySep 08 1999Sep 10 1999We review recent computations of neutral pion photoproduction and Compton scattering on the deuteron in baryon chiral perturbation theory. Progress in extracting the neutron electric dipole amplitude, which is relevant in neutral pion photoproduction, ... More
Cut-Set Bounds for Multimessage Multicast Networks with Independent Channels and Zero-Delay EdgesJun 01 2015Apr 26 2016We consider a communication network consisting of nodes and directed edges that connect the nodes. The network may contain cycles. The communications are slotted where the duration of each time slot is equal to the maximum propagation delay experienced ... More
Broken Chiral Symmetry on a Null PlaneFeb 06 2013Jul 22 2013On a null-plane (light-front), all effects of spontaneous chiral symmetry breaking are contained in the three Hamiltonians (dynamical Poincar\'e generators), while the vacuum state is a chiral invariant. This property is used to give a general proof of ... More
Ground state energy of the interacting Bose gas in two dimensions: an explicit constructionFeb 19 2010The isotropic scattering phase shift is calculated for non-relativistic bosons interacting at low energies via an arbitrary finite-range potential in d spacetime dimensions. Scattering on a (d-1)-dimensional torus is then considered, and the eigenvalue ... More
Nucleon-Nucleon Scattering in the 1/N ExpansionApr 09 2002The nucleon-nucleon 3S1-3D1 coupled-channel problem is solved analytically to leading order in a joint expansion in the quark masses and in 1/N. An approximate expression is derived for the 3S1 scattering length in the large-N limit, and the large-N behavior ... More
Photonic Probes of the Deuteron in Effective Field TheoryDec 12 2000I give a taste of recent progress in using chiral perturbation theory to understand nucleon and deuteron structure.
Chiral Multiplets of Large-N Ground State BaryonsSep 10 1998I show that in the large-N limit the ground state baryons with helicity h fall into an ((N-2h)/4,(N+2h)/4) irreducible representation of SU(2)XSU(2). This representation determines the absolute normalization of the ground state baryon axial vector couplings ... More
A Note on Wess-Zumino Terms and Discrete SymmetriesJul 16 1998Oct 22 1998Sigma models in which the integer coefficient of the Wess-Zumino term vanishes are easy to construct. This is the case if all flavor symmetries are vectorlike. We show that there is a subset of SU(N)XSU(N) vectorlike sigma models in which the Wess-Zumino ... More
In Search of the Chiral RegimeMar 30 2004A critical appraisal is given of a recent analysis of the quark-mass and finite-size dependence of unquenched lattice QCD data for the nucleon mass. We use this forum to estimate the boundary of the chiral regime for nucleon properties.
Can a pseudo-symmetry solve the cosmological constant problem?Feb 05 1995Aug 31 1995A general no-go theorem dampens hope that the cosmological constant problem can be solved by a local symmetry mechanism. The possibility is considered here that this no-go theorem can be avoided by a pseudo-symmetry. A simple macroscopic effective field ... More
Goldstone's Theorem on a Light-Like PlaneAug 04 2015I review various aspects of chiral symmetry and its spontaneous breaking on null planes, including the interesting manner in which Goldstone's theorem is realized and the constraints that chiral symmetry imposes on the null-plane Hamiltonians. Specializing ... More
Nonequilibrium spin current through interacting quantum dotsDec 15 2014We develop a theory for charge and spin current between two canted magnetic leads flowing through a quantum dot with an arbitrary local interaction. For a noncollinear magnetic configuration, we calculate equilibrium and nonequilibrium current biased ... More
High Energy Theorems at Large-NSep 30 1999Sum rules for products of two, three and four QCD currents are derived using chiral symmetry at infinite momentum in the large-N limit. These exact relations among meson decay constants, axialvector couplings and masses determine the asymptotic behavior ... More
Gamma-Deuteron ScatteringMay 21 1999We discuss a recent computation of Compton scattering on the deuteron at photon energies of order the pion mass. An interaction kernel is computed in baryon chiral perturbation theory and sewn to phenomenological deuteron wave functions. As an appetizer, ... More
Flavor Doubling and the Nature of AsymptopiaJun 04 1997We consider the possibility that QCD with N flavors has a useful low-energy description with 2N flavors. Specifically, we investigate a free theory of 2N quarks. Although the free theory is U(N)_L X U(N)_R invariant, it admits a larger U(2N) invariance. ... More
Status of Effective Field Theory of NN ScatteringJun 23 1998I review recent progress in developing a systematic power counting scheme for scattering processes involving more than one nucleon.
Classes of Delay-Independent Multimessage Multicast Networks with Zero-Delay NodesOct 20 2014Sep 11 2015In a network, a node is said to incur a delay if its encoding of each transmitted symbol involves only its received symbols obtained before the time slot in which the transmitted symbol is sent (hence the transmitted symbol sent in a time slot cannot ... More
Low Energy Constants from High Energy TheoremsOct 27 1999New constraints on resonance saturation in chiral perturbation theory are investigated. These constraints arise because each consistent saturation scheme must map to a representation of the full QCD chiral symmetry group. The low-energy constants of chiral ... More
Novel Algebraic Consequences of Chiral SymmetryFeb 05 1997Phenomenologically motivated Lie-algebraic sum rules determine the representations of unbroken SU(2)_L X SU(2)_R filled out by mesons containing a single heavy quark, in the limit that the heavy quark mass goes to infinity. This representation content ... More
Hadronic interactions and nuclear physicsDec 05 2008I give an overview of efforts in the last year to calculate interactions among hadrons using lattice QCD. Results discussed include the extraction of low-energy phase shifts and three-body interactions, and the study of pion and kaon condensation. A critical ... More
Quantum Discrete Symmetry and the Strong CP ProblemJun 04 1997We study a 2N-flavor effective theory of N-flavor QCD. With the axial anomaly accounted for in the effective theory by a 't Hooft interaction, only QCD conserved currents survive. However, there is a residual discrete symmetry with interesting properties. ... More
On the importance of testing gravity at distances less than 1cmFeb 25 1997If the mechanism responsible for the smallness of the vacuum energy is consistent with local quantum field theory, general arguments suggest the existence of at least one unobserved scalar particle with Compton wavelength bounded from below by one tenth ... More
Nuclear Physics from QCDAug 29 2003Recent attempts to make direct contact between QCD and simple nuclear systems are reviewed.
Exploring Baryon Chiral MultipletsMar 03 2003The full QCD chiral symmetry algebra has predictive consequences at low energies. I discuss the ground-state chiral multiplet involving the light baryons and emphasize the special role of the Roper resonance.
Stringy Mass Squared Splittings RevisitedFeb 09 1998An empirically successful mass formula derived long ago from hadronic string models is not explained by symmetries of the QCD lagrangian. Consider that M(rho)^2-M(pi)^2 = M(K*)^2-M(K)^2 to a few percent accuracy. We derive this and other equal spacing ... More
The Advantages of Being VectorlikeOct 08 1998We construct an asymptotically free gauge theory with an SU(2)xSU(2)xU(1) vectorlike flavor symmetry. We show that this gauge theory has properties which provide insight into aspects of low-energy QCD.
Quasi-Minimal, Pseudo-Minimal Systems and Dense OrbitsMar 10 2008In this article the authors research on systems whose union of the dense orbits forms an open set. There are some small results and examples. The article shows that the theorem of LeCalvez and Joccoz does not hold for the punctered torus. Some of the ... More
A Flaring X-ray Source with an Halpha-bright Counterpart toward the SMCNov 11 2008We report the discovery of a flaring X-ray source with an optical counterpart with Halpha emission and red-excess, in the direction of the SMC. A 100 ksec X-ray observation with Chandra detected a flare lasting 6 ksec in the source CXO J005428.9-723107. ... More
Strongly Interacting W's and Z's and the Existence of a Heavy Fourth Generation of FermionsApr 08 1993By employing the dictum that axiomatic principles are devoid of predictive power, we find that the elastic unitarity constraint, applied to strong W$_L$W$_L$ scattering, does not alter the assumed spectrum of intermediate states. We consider intermediate ... More
The Adler-Weisberger DiscrepancySep 05 2016The Adler-Weisberger sum rule for the nucleon axial-vector charge, $g_A$, offers a unique signature of chiral symmetry and its breaking in QCD. Its derivation relies on both algebraic aspects of chiral symmetry, which guarantee the convergence of the ... More
Chiral corrections to the Adler-Weisberger sum ruleSep 05 2016Dec 07 2016The Adler-Weisberger sum rule for the nucleon axial-vector charge, $g_A$, offers a unique signature of chiral symmetry and its breaking in QCD. Its derivation relies on both algebraic aspects of chiral symmetry, which guarantee the convergence of the ... More
Generalized fractal dimensions of invariant measures of full-shift systems over uncountable alphabets: generic behaviorMar 08 2019In this paper we show that, for topological dynamical systems with a dense set (in the weak topology) of periodic measures, a typical (in Baire's sense) invariant measure has, for each $q>0$, zero lower $q$-generalized fractal dimension. This implies, ... More
Generic properties of invariant measures of full-shift systems over perfect separable metric spacesMar 07 2019In this work, we are interested in characterizing typical (generic) dimensional properties of invariant measures associated with the full-shift system, $T$, in a product space whose alphabet is uncountable. %fixed dynamic system and with certain dimensional ... More
Pions in the Pionless Effective Field TheoryApr 17 2002May 13 2002We show that processes involving pions that remain very near their mass-shell can be reliably computed in the pionless effective field theory, with the pion integrated in as a heavy field. As an application, we compute the pion-deuteron scattering amplitude ... More
Partially-Quenched Nucleon-Nucleon ScatteringOct 24 2002Nucleon-nucleon scattering is studied to next-to-leading order in a partially-quenched extension of an effective field theory used to describe multi-nucleon systems in QCD. The partially-quenched nucleon-nucleon amplitudes will play an important role ... More
On twisted Riemannian extensions associated with Szabó metricsApr 19 2016Let $M$ be an $n$-dimensional manifold with a torsion free affine connection $\nabla$ and let $T^*M$ be the cotangent bundle. In this paper, we consider some of the geometrical aspect of a twisted Riemannian extension which provide a link between the ... More
On the Scaling Exponent of Polar Codes for Binary-Input Energy-Harvesting ChannelsJan 06 2016Nov 14 2016This paper investigates the scaling exponent of polar codes for binary-input energy-harvesting (EH) channels with infinite-capacity batteries. The EH process is characterized by a sequence of i.i.d. random variables with finite variances. The scaling ... More
A Proof of the Strong Converse Theorem for Gaussian Broadcast Channels via the Gaussian Poincaré InequalitySep 04 2015Sep 11 2015We prove that 2-user Gaussian broadcast channels admit the strong converse. This implies that every sequence of block codes with an asymptotic average error probability smaller than one is such that all the limit points of the sequence of rate pairs must ... More
How to Renormalize the Gap Equation in High Density QCDMay 18 2000We discuss two technical issues related to the gap equation in high-density QCD: i) how to obtain the asymptotic solution with well controlled approximations, and ii) the renormalization of four-quark operators in the high-density effective field theory. ... More
On twisted Riemannian extensions associated with Szabó metricsApr 19 2016Jan 24 2017Let $M$ be an $n$-dimensional manifold with a torsion free affine connection $\nabla$ and let $T^*M$ be the cotangent bundle. In this paper, we consider some of the geometrical aspect of a twisted Riemannian extension which provide a link between the ... More
On three dimensional affine Szabó manifoldsApr 19 2016In this paper, we consider the cyclic parallel Ricci tensor condition, which is a necessary condition for an affine manifold to be Szab\'o. We show that, in dimension $3$, there are affine manifolds which satisfy the cyclic parallel Ricci tensor but are ... More
A characterization of singular packing subspaces with an application to limit-periodic operatorsApr 28 2016A new characterization of the singular packing subspaces of general bounded self-adjoint operators is presented, which is used to show that the set of operators whose spectral measures have upper packing dimension equal to one is a $G_\delta$ (in suitable ... More
Asymptotic Expansions for Gaussian Channels with Feedback under a Peak Power ConstraintOct 09 2014Oct 13 2014This paper investigates the asymptotic expansion for the size of block codes defined for the additive white Gaussian noise (AWGN) channel with feedback under the following setting: A peak power constraint is imposed on every transmitted codeword, and ... More
Strong Converse for Discrete Memoryless Networks with Tight Cut-Set BoundsJun 15 2016Jun 17 2016This paper proves the strong converse for any discrete memoryless network (DMN) with tight cut-set bound, i.e., whose cut-set bound is achievable. Our result implies that for any DMN with tight cut-set bound and any fixed rate tuple that resides outside ... More
Empirical Output Distribution of Good Delay-Limited Codes for Quasi-Static Fading ChannelsOct 29 2015Nov 14 2016This paper considers delay-limited communication over quasi-static fading channels under a long-term power constraint. A sequence of length-$n$ delay-limited codes for a quasi-static fading channel is said to be capacity-achieving if the codes achieve ... More
Rearranging Pionless Effective Field TheoryNov 17 2000Nov 22 2000We point out a redundancy in the operator structure of the pionless effective field theory which dramatically simplifies computations. This redundancy is best exploited by using dibaryon fields as fundamental degrees of freedom. In turn, this suggests ... More
DVCS-Dissociation of the Deuteron and the EMC EffectDec 07 2004The break-up of the deuteron during deeply-virtual Compton scattering, gamma* d --> gamma(*) n p, is explored. In the effective field theory describing nucleon dynamics at momenta below the pion mass, the EMC effect results from four-nucleon interactions ... More
Baryon Axial Charge in a Finite VolumeApr 15 2004We compute finite-volume corrections to nucleon matrix elements of the axial-vector current. We show that knowledge of this finite-volume dependence --as well as that of the nucleon mass-- obtained using lattice QCD will allow a clean determination of ... More
Automatic Renal Segmentation in DCE-MRI using Convolutional Neural NetworksDec 19 2017Kidney function evaluation using dynamic contrast-enhanced MRI (DCE-MRI) images could help in diagnosis and treatment of kidney diseases of children. Automatic segmentation of renal parenchyma is an important step in this process. In this paper, we propose ... More
Load-Balanced Fractional Repetition CodesFeb 02 2018We introduce load-balanced fractional repetition (LBFR) codes, which are a strengthening of fractional repetition (FR) codes. LBFR codes have the additional property that multiple node failures can be sequentially repaired by downloading no more than ... More
Two-Particle Elastic Scattering in a Finite Volume Including QEDJul 17 2014The presence of long-range interactions violates a condition necessary to relate the energy of two particles in a finite volume to their S-matrix elements in the manner of Luscher. While in infinite volume, QED contributions to low-energy charged particle ... More
Direct Channel Dominance in Goldstone Boson Scattering in the Resonance RegionMar 13 1993We consider the scattering of Goldstone bosons in the range of intermediate energies, and in particular focus our attention on the scattering of pions in the $\rho$-resonance region. The chiral perturbation series is obtained to order $E^4$ from a chiral ... More
Topological Phases of Inhomogeneous SuperconductivityJan 17 2016We theoretically consider the effect of a spatially periodic modulation of the superconducting order parameter on the formation of Majorana fermions induced by a one-dimensional system with magnetic impurities brought into close proximity to an $s$-wave ... More
An Explicit Construction of Optimal Streaming Codes for Channels with Burst and Arbitrary ErasuresMar 18 2019This paper presents a new construction of error correcting codes which achieves optimal recovery of a streaming source over a packet erasure channel. The channel model considered is the sliding window erasure model, with burst and arbitrary losses, introduced ... More
Landau-Lifshitz theory of the longitudinal spin Seebeck effectApr 26 2013Aug 12 2013Thermal-bias-induced spin angular momentum transfer between a paramagnetic metal and ferromagnetic insulator is studied theoretically based on the stochastic Landau-Lifshitz-Gilbert (LLG) phenomenology. Magnons in the ferromagnet establish a nonequilibrium ... More
Empirical Output Distribution of Good Delay-Limited Codes for Quasi-Static Fading ChannelsOct 29 2015Nov 26 2015This paper considers delay-limited communication over quasi-static fading channels under a long-term power constraint. A sequence of length-$n$ delay-limited codes for a quasi-static fading channel is said to be capacity-achieving if the codes achieve ... More
Achievable Rates for Gaussian Degraded Relay Channels with Non-Vanishing Error ProbabilitiesApr 06 2016Oct 18 2016This paper revisits the Gaussian degraded relay channel, where the link that carries information from the source to the destination is a physically degraded version of the link that carries information from the source to the relay. The source and the ... More
Nucleons Properties at Finite Lattice Spacing in Chiral Perturbation TheoryJun 26 2003Properties of the proton and neutron are studied in partially-quenched chiral perturbation theory at finite lattice spacing. Masses, magnetic moments, the matrix elements of isovector twist-2 operators and axial-vector currents are examined at the one-loop ... More
The Role of the Roper in QCDDec 06 2002We show that existing data suggest a simple scenario in which the nucleon, and the Delta and Roper resonances act as chiral partners in a reducible representation of the full QCD chiral symmetry group. We discuss the peculiar interpretation of this scenario ... More
Nucleons in Two-Flavor Partially-Quenched Chiral Perturbation TheoryMar 06 2002Properties of the proton and the neutron are explored in partially-quenched chiral perturbation theory with two non-degenerate light flavors. Masses, magnetic moments, matrix elements of isovector twist-2 operators and axial-vector currents are computed ... More
Nucleon-Nucleon Interactions on the LatticeFeb 08 2002Feb 15 2002We consider the nucleon-nucleon potential in quenched and partially-quenched QCD. The leading one-meson exchange contribution to the potential is found to fall off exponentially at long-distances, in contrast with the Yukawa-type behaviour found in QCD. ... More
Aspects of QCD Current Algebra on a Null PlaneNov 30 2015Consequences of QCD current algebra formulated on a light-like hyperplane are derived for the forward scattering of vector and axial-vector currents on an arbitrary hadronic target. It is shown that current algebra gives rise to a special class of sum ... More
Variation of Fundamental Couplings and Nuclear ForcesJun 12 2002Jul 16 2002The dependence of the nuclear force on standard model parameters plays an important role in bounding time and space variations of fundamental couplings over cosmological time scales. We discuss the quark-mass dependence of deuteron and di-neutron binding ... More
Hadronic Parity-Violation on the LatticeMar 27 2002We motivate lattice QCD studies of the parity-violating pion-nucleon coupling constant and extend flavor-conserving hadronic parity-violation from QCD to partially-quenched QCD. The parity-violating pion-nucleon coupling and the anapole form factor (and ... More
Superfluid Transport in Quantum Spin ChainsOct 26 2018Spin superfluids enable long-distance spin transport through classical ferromagnets by developing topologically stable magnetic textures. For small spins at low dimensions, however, the topological protection suffers from strong quantum fluctuations. ... More
Nonlinear Dynamics in a Magnetic Josephson JunctionOct 07 2011We theoretically consider a Josephson junction formed by a ferromagnetic spacer with a strong spin-orbit interaction or a magnetic spin valve, i.e., a bilayer with one static and one free layer. Electron spin transport facilitates a nonlinear dynamical ... More
Detecting Topological Superconductivity with $\varphi_{0}$ Josephson JunctionsJul 26 2016The interplay of superconductivity, magnetic fields, and spin-orbit interaction lies at the heart of topological superconductivity. Remarkably, the recent experimental discovery of $\varphi_{0}$ Josephson junctions by Szombati et al., Nat. Phys. 12, 568 ... More
An Explicit Rate-Optimal Streaming Code for Channels with Burst and Arbitrary ErasuresApr 11 2019In this paper, we consider transmitting a sequence of messages (a streaming source) over a packet erasure channel, where every source message must be recovered perfectly at the destination subject to a fixed decoding delay. Recently, the capacity of such ... More
The Quark-Mass Dependence of Two-Nucleon SystemsAug 12 2002Jan 30 2003We explore the quark-mass dependence of two-nucleon systems. Allowed regions for the scattering lengths in the 1S0 and 3S1 channels as functions of the light-quark masses are determined from the current uncertainty in strong-interaction parameters that ... More
A Conjecture about HadronsDec 06 2002We conjecture that in the chiral limit of QCD the spectrum of hadrons is comprised of decoupled, reducible chiral multiplets. A simple rule is developed which identifies the chiral representations filled out by the ground-state hadrons. Our arguments ... More
Spin-torque ac impedance in magnetic tunnel junctionsSep 05 2012Subjecting a magnetic tunnel junction (MTJ) to a spin current and/or electric voltage induces magnetic precession, which can reciprocally pump current through the circuit. This results in an ac impedance, which is sensitive to the magnetic field applied ... More
A Proof of the Strong Converse Theorem for Gaussian Multiple Access ChannelsFeb 11 2015Apr 26 2016We prove the strong converse for the $N$-source Gaussian multiple access channel (MAC). In particular, we show that any rate tuple that can be supported by a sequence of codes with asymptotic average error probability less than one must lie in the Cover-Wyner ... More
Strong Converse Theorems for Classes of Multimessage Multicast Networks: A Rényi Divergence ApproachJul 09 2014Jul 31 2015This paper establishes that the strong converse holds for some classes of discrete memoryless multimessage multicast networks (DM-MMNs) whose corresponding cut-set bounds are tight, i.e., coincide with the set of achievable rate tuples. The strong converse ... More
Cut-Set Bounds for Networks with Zero-Delay NodesDec 06 2013Feb 12 2015In a network, a node is said to incur a delay if its encoding of each transmitted symbol involves only its received symbols obtained before the time slot in which the transmitted symbol is sent (hence the transmitted symbol sent in a time slot cannot ... More
On the Scaling Exponent of Polar Codes for Binary-Input Energy-Harvesting ChannelsJan 06 2016Apr 26 2016This paper investigates the scaling exponent of polar codes for binary-input energy-harvesting (EH) channels with infinite-capacity batteries. The EH process is characterized by a sequence of i.i.d. random variables with finite variances. The scaling ... More
Non-Asymptotic Achievable Rates for Gaussian Energy-Harvesting Channels: Best-Effort and Save-and-TransmitMay 08 2018Jan 14 2019An additive white Gaussian noise energy-harvesting channel with an infinite-sized battery is considered. The energy arrival process is modeled as a sequence of independent and identically distributed random variables. The channel capacity $\frac{1}{2}\log(1+P)$ ... More
Uncertainty Quantification in Lattice QCD Calculations for Nuclear PhysicsOct 11 2014The numerical technique of Lattice QCD holds the promise of connecting the nuclear forces, nuclei, the spectrum and structure of hadrons, and the properties of matter under extreme conditions with the underlying theory of the strong interactions, quantum ... More
Site recurrence of open and unitary quantum walks on the lineJul 25 2016We study the problem of site recurrence of discrete time nearest neighbor open quantum random walks (OQWs) on the integer line, proving basic properties and some of its relations with the corresponding problem for unitary (coined) quantum walks (UQWs). ... More
The Magnetic Field of the Ultraluminous X-ray Pulsar M82 X-2Nov 20 2014Jun 21 2016Pulsations were recently detected from the ultraluminous X-ray source X-2 in M82. The newly discovered pulsar has been described as a common neutron star with a 1 TG magnetic field that accretes above the Eddington rate and as a magnetar-like pulsar with ... More
Renormalization Group Improved Gap Equation for Color SuperconductorsApr 06 2000The renormalization group is used to resum leading logarithmic contributions of the form alpha_s^{n+1} beta_0^n log^n (Delta/mu) to the gap equation appropriate for high density QCD. The scale dependence of the strong coupling constant alpha_s increases ... More
Impurity Induced Quantum Phase Transitions and Magnetic Order in Conventional Superconductors: Competition between Bound and Quasiparticle statesMar 30 2015We theoretically study bound states generated by magnetic impurities within conventional $s$-wave superconductors, both analytically and numerically. In determining the effect of the hybridization of two such bound states on the energy spectrum as a function ... More
Refined scales of decaying rates of operator semigroups on Hilbert spaces: typical behaviourApr 20 2018We obtain refined scales of decaying rates of operator semigroups on Hilbert spaces; more specifically, we show that the decaying rates of the orbits of these semigroups, typically in Baire's sense, depend on subsequences of time going to infinity. For ... More
Non-Asymptotic Achievable Rates for Energy-Harvesting Channels using Save-and-TransmitJul 09 2015Apr 26 2016This paper investigates the information-theoretic limits of energy-harvesting (EH) channels in the finite blocklength regime. The EH process is characterized by a sequence of i.i.d. random variables with finite variances. We use the save-and-transmit ... More
Strong-Isospin Violation in the Neutron-Proton Mass Difference from Fully-Dynamical Lattice QCD and PQQCDMay 16 2006We determine the strong-isospin violating component of the neutron-proton mass difference from fully-dynamical lattice QCD and partially-quenched QCD calculations of the nucleon mass, constrained by partially-quenched chiral perturbation theory at one-loop ... More
Constraints on the Universe as a Numerical SimulationOct 04 2012Nov 09 2012Observable consequences of the hypothesis that the observed universe is a numerical simulation performed on a cubic space-time lattice or grid are explored. The simulation scenario is first motivated by extrapolating current trends in computational resource ... More
Meson Masses in High Density QCDFeb 18 2000The low-energy effective theories for the two- and three-flavor color-superconductors arising in the high density limit of QCD are discussed. Using an effective field theory to describe quarks near the fermi surface, we compute the masses of the pseudo-Goldstone ... More
Density-functional investigation of the rhombohedral to simple cubic phase transition of arsenicOct 09 2008We report on our investigation of the crystal structure of arsenic under compression, focusing primarily on the pressure-induced A7 to simple cubic (sc) phase transition. The two-atom rhombohedral unit cell is subjected to pressures ranging from 0 GPa ... More
Universal Quantum Computation with Hybrid Spin-Majorana QubitsFeb 22 2016We theoretically propose a set of universal quantum gates acting on a hybrid qubit formed by coupling a quantum dot spin qubit and Majorana fermion qubit. First, we consider a quantum dot tunnel-coupled to two topological superconductors. The effective ... More