Research archive
arXiv papers from February 2013
The most recent 100 records published that month. Open any paper for its original abstract, citation metadata, related research, and reading tools.
Stephen T. Bryson, Jon M. Jenkins, Ronald L. Gilliland, Joseph D. Twicken
The Kepler Mission was launched on March 6, 2009 to perform a photometric survey of more than 100,000 dwarf stars to search for Earth-size planets with the transit technique. The reliability of the resulting planetary candidate list relies on the ability to identify and remove false positives. Major sources of astrophysical false positives are planetary tran
Binh T. Nguyen, Andrey L. Delytsin, Denis S. Grebenkov
We consider the eigenvalue problem for the Laplace operator in a planar domain which can be decomposed into a bounded domain of arbitrary shape and elongated \branches" of variable cross-sectional profiles. When the eigenvalue is smaller than a prescribed threshold, the corresponding eigenfunction decays exponentially along each branch. We prove this behavio
Maziyar Hamdi, Vikram Krishnamurthy, George Yin
This paper considers a Markov-modulated duplication-deletion random graph where at each time instant, one node can either join or leave the network; the probabilities of joining or leaving evolve according to the realization of a finite state Markov chain. The paper comprises of 2 results. First, motivated by social network applications, we analyze the asymp
Gary Steigman
According to conventional wisdom, in the standard model (SM) of particle physics and cosmology the effective number of neutrinos is Neff=3 (more precisely, 3.046). In extensions of the standard model allowing for the presence of DeltaNnu equivalent neutrinos (or dark radiation), Neff is generally >3. The canonical results are reconsidered here, revealing tha
Badar Rashid, Michel Destrade, Michael Gilchrist
Unconfined compression tests are more convenient to perform on cylindrical samples of brain tissue than tensile tests in order to estimate mechanical properties of the brain tissue because they allow for homogeneous deformations. The reliability of these tests depends significantly on the amount of friction generated at the specimen/platen interface. Thus, t
Tai-Fu Feng, Shu-Min Zhao, Hai-Bin Zhang, Yin-Jie Zhang
Assuming that the Yukawa couplings between the Higgs and exotic quarks cannot be ignored, we analyze the signals of decay channels $h\rightarrow\gamma\gamma$ and $h\rightarrow VV^*\;(V=Z,\;W)$ with the Higgs mass around $125\;{\rm GeV}$ in a supersymmetric extension of the standard model where baryon and lepton numbers are local gauge symmetries. Adopting so
Badar Rashid, Michel Destrade, Michael D. Gilchrist
Mechanical characterization of brain tissue has been investigated extensively by various research groups over the past fifty years. These properties are particularly important for modelling Traumatic Brain Injury (TBI). In this research, we present the design and calibration of a High Rate Tension Device (HRTD) capable of performing tests up to a maximum str
Bogdan State, Patrick Park, Ingmar Weber, Yelena Mejova
In The Clash of Civilizations, Samuel Huntington argued that the primary axis of global conflict was no longer ideological or economic but cultural and religious, and that this division would characterize the "battle lines of the future." In contrast to the "top down" approach in previous research focused on the relations among nation states, we focused on t
Zoltan Esik
We show that three fixed point structures equipped with (sequential) composition, a sum operation, and a fixed point operation share the same valid equations. These are the theories of (context-free) languages, (regular) tree languages, and simulation equivalence classes of (regular) synchronization trees (or processes). The results reveal a close relationsh
- Quasar Absorption Lines in the Far Ultraviolet: An Untapped Gold Mine for Galaxy Evolution Studiesastro-ph.CO
Todd Tripp
This white paper emphasizes the potential of QSO absorption lines in the rest-frame far/extreme UV at rest-frame wavelengths from ~500 to 2000 A. In this wavelength range, species such as Ne VIII, Na IX, and Mg X can be detected, providing diagnostics of gas with temperatures >> 10^{6} K, as well as banks of adjacent ions such as O I, O II, O III, O IV, O V,
Lynn Cominsky, Kevin McLin, Aurore Simonnet, the Fermi Education
During the past twelve years, NASA's Fermi Gamma-ray Space Telescope has supported a wide range of Education and Public Outreach (E/PO) activities, targeting K-14 students and the general public. The purpose of the Fermi E/PO program is to increase student and public understanding of the science of the high-energy Universe, through inspiring, engaging and ed
Florent Madelaine, Barnaby Martin
We study the (non-uniform) quantified constraint satisfaction problem QCSP(H) as H ranges over partially reflexive cycles. We obtain a complexity-theoretic dichotomy: QCSP(H) is either in NL or is NP-hard. The separating conditions are somewhat esoteric hence the epithet "wavy line of tractability".
Badar Rashid, Michel Destrade, Michael Gilchrist
Extensive research has been carried out for at least 50 years to understand the mechanical properties of brain tissue in order to understand the mechanisms of traumatic brain injury (TBI). The observed large variability in experimental results may be due to the inhomogeneous nature of brain tissue and to the broad range of test conditions. However, test temp
- Atomistic Boron-Doped Graphene Field Effect Transistors: A Route towards Unipolar Characteristicscond-mat.mes-hall
Paolo Marconcini, Alessandro Cresti, Francois Triozon, Gianluca Fiori
We report fully quantum simulations of realistic models of boron-doped graphene-based field effect transistors, including atomistic details based on DFT calculations. We show that the self-consistent solution of the three-dimensional (3D) Poisson and Schr\"odinger equations with a representation in terms of a tight-binding Hamiltonian manages to accurately r
Vijay Kamble, Jean Walrand
Distributions with a heavy tail are difficult to estimate. If the design of a scheduling policy is sensitive to the details of heavy tail distributions of the service times, an approximately optimal solution is difficult to obtain. This paper shows that the optimal scheduling of an M/G/1 queue with heavy tailed service times does not present this difficulty
- Multiple light scattering on the F = 1 - F' = 0 transition in a cold and high density 87Rb vaporphysics.atom-ph
S. Balik, A. L. Win, M. D. Havey, A. S. Sheremet
We report an experimental study of near resonance light scattering on the $F = 1 \rightarrow F' = 0$ component of the $D_2$ line in atomic $^{87}Rb$. Experiments are performed on spatially bi-Gaussian ultracold gas samples having peak densities ranging from about $5 \cdot 10^{12} - 5 \cdot 10^{13}$ atoms/cm$^{3}$ and for a range of resonance saturation param
- The merger fraction of active and inactive galaxies in the local Universe through an improved non-parametric classificationastro-ph.GA
Stefano Cotini, Emanuele Ripamonti, Alessandro Caccianiga, Monica Colpi
We investigate the possible link between mergers and the enhanced activity of supermassive black holes (SMBHs) at the centre of galaxies, by comparing the merger fraction of a local sample (0.003 =< z < 0.03) of active galaxies - 59 active galactic nuclei (AGN) host galaxies selected from the all-sky Swift BAT (Burst Alert Telescope) survey - with an appropr
Min Chih Lin, Michel J. Mizrahi, Jayme L. Szwarcfiter
Say that an edge of a graph $G$ dominates itself and every other edge adjacent to it. An edge dominating set of a graph $G=(V,E)$ is a subset of edges $E' \subseteq E$ which dominates all edges of $G$. In particular, if every edge of $G$ is dominated by exactly one edge of $E'$ then $E'$ is a dominating induced matching. It is known that not every graph admi
J. M. Corral-Santana, J. Casares, T. Muñoz-Darias, P. Rodríguez-Gil
Stellar-mass black holes (BHs) are mostly found in X-ray transients, a subclass of X-ray binaries that exhibit violent outbursts. None of the 50 Galactic BHs known show eclipses, which is surprising for a random distribution of inclinations. Swift J1357.2-0933 is a very faint X-ray transient detected in 2011. On the basis of spectroscopic evidence, we show t
Matias Abel Oscar Quiroga
We report ab initiocomputations with the Vienna ab Initio Simulation Package (VASP) aimed at elucidating the adsorption mechanism of graphene-like structures on (111) Pd, Pt, and Ni surfaces. To study the adsorption properties, we simulate an already-formed graphene layer. We present a comparative discussion of the graphene interactions with the three metals
Lang Feng, Lea-Laetitia Pontani, Remi Dreyfus, Paul Chaikin
The specificity and thermal reversibility of DNA interactions have enabled the self-assembly of crystal structures, self-replicating materials and colloidal molecules. Grafting DNA onto liquid interfaces of emulsions leads to exciting new architectural possibilities due to the mobility of the DNA ligands and the patches they form between bound droplets. Here
Anatoly Manita
We consider a stochastic model of clock synchronization in a wireless network consisting of N sensors interacting with one dedicated accurate time server. For large N we find an estimate of the final time sychronization error for global and relative synchronization. Main results concern a behavior of the network on different time scales $t=t_N \to \infty$, $
Maik Gröger, Brian R. Hunt
The Kaplan-Yorke conjecture states that for "typical" dynamical systems with a physical measure, the information dimension and the Lyapunov dimension coincide. We explore this conjecture in a neighborhood of a system for which the two dimensions do not coincide because the system consists of two uncoupled subsystems. We are interested in whether coupling "ty
Chris Evans, Mathieu Puech, Beatriz Barbuy, Nate Bastian
The workhorse instruments of the 8-10m class observatories have become their multi-object spectrographs (MOS), providing comprehensive follow-up to both ground-based and space-borne imaging. With the advent of deeper imaging surveys from, e.g., the HST and VISTA, there are a plethora of spectroscopic targets which are already beyond the sensitivity limits of
B. Allen, B. Knispel, J. M. Cordes, J. S. Deneva
Einstein@Home aggregates the computer power of hundreds of thousands of volunteers from 193 countries, to search for new neutron stars using data from electromagnetic and gravitational-wave detectors. This paper presents a detailed description of the search for new radio pulsars using Pulsar ALFA survey data from the Arecibo Observatory. The enormous computi
- Physical Properties of Spectroscopically-Confirmed Galaxies at z >= 6. II. Morphology of the Rest-Frame UV Continuum and Lyman-alpha Emissionastro-ph.CO
Linhua Jiang, Eiichi Egami, Xiaohui Fan, Rogier A. Windhorst
We present a detailed structural and morphological study of a large sample of spectroscopically-confirmed galaxies at z >= 6, using deep HST near-IR broad-band images and Subaru optical narrow-band images. The galaxy sample consists of 51 Lyman-alpha emitters (LAEs) at z ~ 5.7, 6.5, and 7.0, and 16 Lyman-break galaxies (LBGs) at 5.9 < z < 6.5. These galaxies
Peter C. Heinig
If eps > 0 and p >= n^{-1/2 + eps}, in a binomial random graph G(n,p) a.a.s. the set of cycles which can be constructed as a symmetric difference of Hamilton circuits is as large as parity by itself permits (all cycles if n is odd, all even cycles if n is even). Moreover, every p which ensures the above property a.a.s. must necessarily be such that for any c
M. Silarski
We present a new search for the $K_S \to 3\pi^0$ decay performed with the KLOE detector operating at the DA$\Phi$NE $\phi$--factory. The $K_S$ mesons were tagged via registration of $K_L$ mesons which crossed the drift chamber without decaying and interacted with the KLOE electromagnetic calorimeter. The $K_S \to 3\pi^0$ decay was then searched requiring six
- Physical Properties of Spectroscopically-Confirmed Galaxies at z >= 6. I. Basic Characteristics of the Rest-Frame UV Continuum and Lyman-alpha emissionastro-ph.CO
Linhua Jiang, Eiichi Egami, Matthew Mechtley, Xiaohui Fan
We present deep HST near-IR and Spitzer mid-IR observations of a large sample of spectroscopically-confirmed galaxies at z >= 6. The sample consists of 51 Lyman-alpha emitters (LAEs) at z ~ 5.7, 6.5, and 7.0, and 16 Lyman-break galaxies (LBGs) at 5.9 < z < 6.5. The near-IR images were mostly obtained with WFC3 in the F125W and F160W bands, and the mid-IR ima
Lamiaa Fattouh Ibrahim, Manal El Harby
With the rapid development in mobile network effective network planning tool is needed to satisfy the need of customers. However, deciding upon the optimum placement for the base stations (BS) to achieve best services while reducing the cost is a complex task requiring vast computational resource. This paper addresses antenna placement problem or the cell pl
Meifeng Lin
We report the status of our nucleon structure calculations with 2+1 flavors of domain wall fermions on the RBC-UKQCD $32^3\times64$ gauge ensembles with the Iwasaki+DSDR action. These ensembles have a fixed lattice scale of 1/a = 1.37 GeV, and two pion masses of about 170 and 250 MeV. Preliminary results for the isovector electromagnectic form factors and th
Dmitry Solenov, Sophia E. Economou, Thomas L. Reinecke
We propose a fast, scalable all-optical design for arbitrary two-qubit operations for defect qubits in diamond (NV centers) and in silicon carbide, which are promising candidates for room temperature quantum computing. The interaction between qubits is carried out by microcavity photons. The approach uses constructive interference from higher energy excited
Tomasz Kania, Piotr Koszmider, Niels Jakob Laustsen
Denote by $[0,\omega_1)$ the locally compact Hausdorff space consisting of all countable ordinals, equipped with the order topology, and let $C_0[0,\omega_1)$ be the Banach space of scalar-valued, continuous functions which are defined on $[0,\omega_1)$ and vanish eventually. We show that a weakly$^*$ compact subset of the dual space of $C_0[0,\omega_1)$ is
Benjamin D. Oppenheimer, Joop Schaye
We model the time-dependent evolution of metal-enriched intergalactic and circumgalactic gas exposed to the fluctuating radiation field from an active galactic nucleus (AGN). We consider diffuse gas densities (n_H=10^-5-10^-3 cm^-3) exposed to the extra-galactic background (EGB) and initially in thermal equilibrium (T \sim 10^4-10^4.5 K). Once the proximate
Alireza Aghasi, Justin Romberg
This paper introduces a new shape-based image reconstruction technique applicable to a large class of imaging problems formulated in a variational sense. Given a collection of shape priors (a shape dictionary), we define our problem as choosing the right elements and geometrically composing them through basic set operations to characterize desired regions in
- Strong Convergence of Euler Approximations of Stochastic Differential Equations with Delay under Local Lipschitz Conditionmath.PR
Chaman Kumar, Sotirios Sabanis
The strong convergence of Euler approximations of stochastic delay differential equations is proved under general conditions. The assumptions on drift and diffusion coefficients have been relaxed to include polynomial growth and only continuity in the arguments corresponding to delays. Furthermore, the rate of convergence is obtained under one-sided and poly
Liviu P. Dinu, Catalin Zara
For a right invariant distance on a permutation space $S_n$ we give a sufficient condition for the cardinality of a ball of radius $R$ to grow polynomially in $n$ for fixed $R$. For the distance $\ell_1$ we show that for an integer $k$ the cardinality of a sphere of radius $2k$ in $S_n$ (for $n \geqslant k$) is a polynomial of degree $k$ in $n$ and determine
- Is the regime with shot noise suppression by a factor 1/3 achievable in semiconductor devices with mesoscopic dimensions?cond-mat.mes-hall
Paolo Marconcini, Massimo Macucci, Demetrio Logoteta, Massimo Totaro
We discuss the possibility of diffusive conduction and thus of suppression of shot noise by a factor 1/3 in mesoscopic semiconductor devices with two-dimensional and one-dimensional potential disorder, for which existing experimental results do not provide a conclusive result. On the basis of our numerical analysis, we conclude that it is quite difficult to
Sylwester Zając
We describe all complex geodesics in convex tube domains. In the case when the base of a convex tube domain does not contain any real line, the obtained description involves the notion of boundary measure of a holomorphic map and it is expressed in the language of real Borel measures on the unit circle. Applying our result, we calculate all complex geodesics
- Cell-type-specific microarray data and the Allen atlas: quantitative analysis of brain-wide patterns of correlation and densityq-bio.NC
Pascal Grange, Michael Hawrylycz, Partha P. Mitra
The Allen Atlas of the adult mouse brain is used to estimate the region-specificity of 64 cell types whose transcriptional profile in the mouse brain has been measured in microarray experiments. We systematically analyze the preliminary results presented in [arXiv:1111.6217], using the techniques implemented in the Brain Gene Expression Analysis toolbox. In
Yoshitomo Kamiya, Cristian D. Batista
Quantum fluctuations become particularly relevant in highly frustrated quantum magnets and can lead to new states of matter. We provide a simple and robust scenario for inducing magnetic vortex crystals in frustrated Mott insulators. By considering a quantum paramagnet that has a gapped spectrum with six-fold degenerate low energy modes, we study the magneti
- Hard and soft bounds in the evolution of Ubuntu packages. A lesson for species body masses?physics.soc-ph
Marco Gherardi, Salvatore Mandrà, Bruno Bassetti, Marco Cosentino Lagomarsino
Open-source software is a complex system; its development depends on the self-coordinated action of a large number of agents. This study follows the size of the building blocks, called "packages", of the Ubuntu Linux operating system over its entire history. The analysis reveals a multiplicative diffusion process, constrained by size-dependent bounds, drivin
Paolo Aluffi
We propose an explicit formula for the Segre classes of monomial subschemes of nonsingular varieties, such as schemes defined by monomial ideals in projective space. The Segre class is expressed as a formal integral on a region bounded by the corresponding Newton polyhedron. We prove this formula for monomial ideals in two variables and verify it for some fa
R. V. Vasudevan, A. C. Fabian, R. F. Mushotzky, M. Meléndez
The Effective Eddington Limit for dusty gas surrounding AGN is lower than the canonical Eddington limit for hydrogen gas. Previous results from the Swift/BAT 9-month catalogue suggested that in the overwhelming majority of local AGN, the dusty absorbing gas is below this Effective Eddington limit, implying that radiation pressure is insufficient to blow away
Baojiu Li, Gong-Bo Zhao, Kazuya Koyama
There has been a lot of research interest in modified gravity theories which utilise the Vainshtein mechanism to recover standard general relativity in regions with high matter density, such as the Dvali-Gabadadze-Porrati and Galileon models. The strong nonlinearity in the field equations of these theories implies that accurate theoretical predictions could
Philippe Brax, Anne-C. Davis, Baojiu Li, Hans A. Winther
In this work we systematically study the linear and nonlinear structure formation in chameleon theories of modified gravity, using a generic parameterisation which describes a large class of models using only 4 parameters. For this we have modified the N-body simulation code ECOSMOG to perform a total of 65 simulations for different models and parameter valu
- The Lyman alpha Reference Sample: Extended Lyman alpha Halos Produced at Low Dust Contentastro-ph.CO
Matthew Hayes, Göran Östlin, Daniel Schaerer, Anne Verhamme
We report on new imaging observations of the Lyman alpha emission line (Lya), performed with the Hubble Space Telescope, that comprise the backbone of the Lyman alpha Reference Sample (LARS). We present images of 14 starburst galaxies at redshifts 0.028 < z < 0.18 in continuum-subtracted Lya, Halpha, and the far ultraviolet continuum. We show that Lya is emi
- Energy conservation and gravity waves in sound-proof treatments of stellar interiors: Part II Lagrangian constrained analysisastro-ph.SR
Geoffrey M. Vasil, Daniel Lecoanet, Benjamin P. Brown, Toby S. Wood
The speed of sound greatly exceeds typical flow velocities in many stellar and planetary interiors. To follow the slow evolution of subsonic motions, various sound-proof models attempt to remove fast acoustic waves whilst retaining stratified convection and buoyancy dynamics. In astrophysics, anelastic models typically receive the most attention in the class
Denis Krotov, Vladimir Potapov
A function $f:\{0,...,q-1\}^n\to\{0,...,q-1\}$ invertible in each argument is called a latin hypercube. A collection $(\pi_0,\pi_1,...,\pi_n)$ of permutations of $\{0,...,q-1\}$ is called an autotopism of a latin hypercube $f$ if $\pi_0f(x_1,...,x_n)=f(\pi_1x_1,...,\pi_n x_n)$ for all $x_1$, ..., $x_n$. We call a latin hypercube isotopically transitive (topo
Mattias Blennow, Pilar Coloma, Andrea Donini, Enrique Fernandez-Martinez
We evaluate the probability of future neutrino oscillation facilities to discover leptonic CP violation and/or measure the neutrino mass hierarchy. We study how this probability is affected by positive or negative hints for these observables to be found at T2K and NOvA. We consider the following facilities: LBNE; T2HK; and the 10 GeV Neutrino Factory (NF10),
Denis Krotov
We derive recursive and direct formulas for the interweight distribution of an equitable partition of a hypercube. The formulas involve a three-variable generalization of the Krawtchouk polynomials. Keywords: equitable partition; regular partition; partition design; strong distance invariance; interweight distribution; distance distribution; Krawtchouk polyn
- Weak phase stiffness and nature of the quantum critical point in underdoped cupratescond-mat.supr-con
Yucel Yildirim, Wei Ku
We demonstrate that the zero-temperature superconducting phase diagram of underdoped cuprates can be quantitatively understood in the strong binding limit, using only the experimental spectral function of the "normal" pseudo-gap phase without any free parameter. In the prototypical (La$_{1-x}$Sr$_x$)$_2$CuO$_4$, a kinetics-driven $d$-wave superconductivity i
Andrew M. Childs, Stacey Jeffery, Robin Kothari, Frederic Magniez
We present an extension to the quantum walk search framework that facilitates quantum walks with nested updates. We apply it to give a quantum walk algorithm for 3-Distinctness with query complexity ~O(n^{5/7}), matching the best known upper bound (obtained via learning graphs) up to log factors. Furthermore, our algorithm has time complexity ~O(n^{5/7}), im
Greg Knese, John E. McCarthy, Kabe Moen
We study two questions. When does a function belong to the union of Lebesgue spaces and when does a function have an $A_1$ majorant? We show these questions are fundamentally related. For functions restricted to a fixed cube we prove that the following are equivalent: a function belongs to $L^p$ for some $p>1$; the function has an $A_1$ majorant; for any $p>
Bahman Ahmadi, Karen Meagher
A subset $S$ of the alternating group on $n$ points is {\it intersecting} if for any pair of permutations $\pi,\sigma$ in $S$, there is an element $i\in \{1,\dots,n\}$ such that $\pi(i)=\sigma(i)$. We prove that if $S$ is intersecting, then $|S|\leq \frac{(n-1)!}{2}$. Also, we prove that if $n \geq 5$, then the only sets $S$ that meet this bound are the cose
Chi Xiong
We apply the Callan-Harvey anomaly inflow mechanism to the study of QCD (chromoelectric) flux tubes, quark (pair)-creation and chiral magnetic effect, using new variables from the Cho-Faddeev-Niemi decomposition of the gauge potential. A phenomenological description of chromoelectric flux tubes is obtained by studying a gauged Nambu-Jona-Lasinio effective La
Karol Kampf
Present status of odd-intrinsic sector of low energy QCD is summarized. The two-photon decay of neutral pion is shortly discussed and its connection with the pion decay constant is analysed. A theoretical tool, the leading-log calculation is also presented, its connection with anomalous sector shown and some new results given.
Daniel Z. Freedman, Silviu S. Pufu
We find new supersymmetric backgrounds of ${\cal N} = 8$ gauged supergravity in four Euclidean dimensions that are dual to deformations of ABJM theory on $S^3$. The deformations encode the most general choice of $U(1)_R$ symmetry used to define the theory on $S^3$. We work within an ${\cal N} = 2$ truncation of the ${\cal N} = 8$ supergravity theory obtained
- Approximative solution of the spin free Hamiltonian involving only scalar potential for the quark-antiquark systemmath-ph
Yoon Seok Choun
In earlier papers [3,4,5,6] Gursey et al. showed development of a bilocal baryon-meson field from two quark-antiquark fields. The Hamiltonian in the case of vanishing quark masses was shown to have a very good agreement with experiments [5]. The theory for vanishing mass was solved using Confluent Hypergeometric functions [6]. In this paper I construct the n
Kresimir Kumericki, Dieter Mueller, Morgan Murray
We report on the status of the phenomenological access of generalized parton distributions from photon and meson electroproduction off proton. Thereby, we emphasize the role of HERMES data for deeply virtual Compton scattering, which allows us to map various asymmetries into the space of Compton form factors.
L. Rondin, J. P. Tetienne, S. Rohart, A. Thiaville
Despite decades of advances in magnetic imaging, obtaining direct, quantitative information with nanometer scale spatial resolution remains an outstanding challenge. Recently, a new technique has emerged that employs a single nitrogen-vacancy (NV) defect in diamond as an atomic-size magnetometer. Although NV magnetometry promises significant advances in magn
Paul C. Duffell, Andrew I. MacFadyen
We numerically calculate the growth and saturation of the Rayleigh-Taylor instability caused by the deceleration of relativistic outflows with Lorentz factor {\Gamma} = 10, 30, and 100. The instability generates turbulence whose scale exhibits strong dependence on Lorentz factor, as only modes with angular size smaller than 1/{\Gamma} can grow. We develop a
Junjie Liu, Enrique del Barco, Stephen Hill
This chapter takes a microscopic view of quantum tunneling of magnetization (QTM) in single-molecule magnets (SMMs), focusing on the interplay between exchange and anisotropy. Careful consideration is given to the relationship between molecular symmetry and the symmetry of the spin Hamiltonian that dictates QTM selection rules. Higher order interactions that
David H. Lyth, Mindaugas Karčiauskas
The inflaton might be coupled to a gauge field through a term f^2(\phi) F_\mu\nu F^\mu\nu. If f \propto a^{-2} where a(t) is the scale factor, the perturbation \delta W of the gauge field generates a potentially observable statistically anisotropic contribution to the primordial curvature perturbation during slow-roll inflation. The spectrum and bispectrum o
Martin Miglioli
This note will present a new proof of the fact that every uniformly bounded group of invertible elements in a finite von Neumann algebra is similar to a unitary group. The proof involves metric geometric arguments in the non-positively curved space of positive invertible operators of the algebra; in 1974 Vasilescu and Zsido proved this result using the Ryll-
Faouzi Ammar, Zeyneb Ejbehi, Abdenacer Makhlouf
The purpose of this paper is to study global deformations of Hom-Leibniz algebras. We introduce a cohomology for Hom-Leibniz algebras with values in a Hom-module, characterize versal deformations and provide examples.
Krzysztof Argasinski, Mark Broom
This paper further develops work from a previous article which introduced a new way of modelling evolutionary game models with an emphasis on ecological realism, concerned with how ecological factors determine payoffs in evolutionary games. The current paper is focused on the impact of selectively neutral factors (i.e. those that are the same for all strateg
Andrew V. Lelechenko
N. Minculete has introduced a concept of divisors of order $r$: integer $d=p_1^{b_1}\cdots p_k^{b_k} $ is called a divisor of order $r$ of $n=p_1^{a_1}\cdots p_k^{a_k}$ if $d \mid n$ and $b_j\in\{r, a_j\}$ for $j=1,\ldots,k$. One can consider respective divisor function $\tau^{(r)}$ and sum-of-divisors function $\sigma^{(r)}$. In the present paper we investi
Volker Crede, Winston Roberts
The composite nature of baryons manifests itself in the existence of a rich spectrum of excited states, in particular in the important mass region 1-2 GeV for the light-flavoured baryons. The properties of these resonances can be identified by systematic investigations using electromagnetic and strong probes, primarily with beams of electrons, photons, and p
A. Pourret, G. Knebel, G. Lapertot, T. D. Matsuda
We report thermoelectric and resitivity measurements of antiferromagnetic heavy fermion compound YRh2Si2 at low temperatures down and under high magnetic field. At low temperature, the thermoelectric power and the resistivity present several distinct anomalies as a function of field around H_0 ~ 9.5 T when the magnetic polarization reaches a critical value.
Michele Cirafici
Donaldson-Thomas theory on a Calabi-Yau can be described in terms of a certain six-dimensional cohomological gauge theory. We introduce a certain class of defects in this gauge theory which generalize surface defects in four dimensions. These defects are associated with divisors and are defined by prescribing certain boundary conditions for the gauge fields.
- Gaussianity revisited: Exploring the Kibble-Zurek mechanism with superconducting ringscond-mat.supr-con
D. J. Weir, R. Monaco, V. P. Koshelets, J. Mygind
In this paper we use spontaneous flux production in annular superconductors to shed light on the Kibble-Zurek scenario. In particular, we examine the effects of finite size and external fields, neither of which is directly amenable to the KZ analysis. Supported by 1D and 3D simulations, the properties of a superconducting ring are seen to be well represented
N. Metwally, A. Sagheer
The capacity of accelerated channel is investigated for different classes of initial states. It is shown that, the capacities of the travelling channels depend on the frame in which the accelerated channels are observed in and the initial shared state between the partners. In some frames, the capacities decay as the accelerations of both qubit increase. The
- Ab Initio Calculations of Even Oxygen Isotopes with Chiral Two- Plus Three-Nucleon Interactionsnucl-th
H. Hergert, S. Binder, A. Calci, J. Langhammer
We formulate the In-Medium Similarity Renormalization Group (IM-SRG) for open-shell nuclei using a multi-reference formalism based on a generalized Wick theorem introduced in quantum chemistry. The resulting multi-reference IM-SRG (MR-IM-SRG) is used to perform the first ab initio study of even oxygen isotopes with chiral NN and 3N Hamiltonians, from the pro
Barbara Trzeciak
In this proceedings the recent STAR results of $J/\psi$ and $\Upsilon$ production in $p+p$, $d$+Au and Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV at mid-rapidity are reported. $J/\psi$ $p_{T}$ spectra in $p+p$ and Au+Au collisions for both low and high $p_{T}$ are shown. $J/\psi$ nuclear modification factor ($R_{AA}$) in $d$+Au and Au+Au collisions and $\
George F R Ellis
This paper extends the work of a previous paper [arXiv:1208.2611] on the flow of time, to consider the origin of the arrow of time. It proposes that a `past condition' cascades down from cosmological to micro scales, being realized in many microstructures and setting the arrow of time at the quantum level by top-down causation. This physics arrow of time the
Feng Yan, Philippe Martins, Laurent Decreusefond
Homology theory has attracted great attention because it can provide novel and powerful solutions to address coverage problems in wireless sensor networks. They usually use an easily computable algebraic object, Rips complex, to detect coverage holes. But Rips complex may miss some coverage holes in some cases. In this paper, we investigate homology-based co
Se Young Park, Andrew J. Millis
We present calculations of the charge density profile, subband occupancy and ellipsometry spectra of the electron gas at the LaAlO3/SrTiO3 interface. The calculations employ self-consistent Hartree and random phase approximations, a tight binding parametrization of the band structure and a model for the optical phonon of SrTiO3. The dependence of the spatial
Feng Yan, Anais Vergne, Philippe Martins, Laurent Decreusefond
Homology theory provides new and powerful solutions to address the coverage problems in wireless sensor networks (WSNs). They are based on algebraic objects, such as Cech complex and Rips complex. Cech complex gives accurate information about coverage quality but requires a precise knowledge of the relative locations of nodes. This assumption is rather stron
- Symmetric solutions to dispersionless 2D Toda hierarchy, Hurwitz numbers and conformal dynamicsmath.CO
S. M. Natanzon, A. V. Zabrodin
We explicitly construct the series expansion for a certain class of solutions to the 2D Toda hierarchy in the zero dispersion limit, which we call symmetric solutions. We express the Taylor coefficients through some universal combinatorial constants and find recurrence relations for them. These results are used to obtain new formulas for the genus 0 double H
- Nonlinear optical effects of ultrahigh-Q silicon photonic nanocavities immersed in superfluid heliumphysics.optics
Xiankai Sun, Xufeng Zhang, Carsten Schuck, Hong X. Tang
Photonic nanocavities are a key component in many applications because of their capability of trapping and storing photons and enhancing interactions of light with various functional materials and structures. The maximal number of photons that can be stored in silicon photonic cavities is limited by the free-carrier and thermo-optic effects at room temperatu
J. Bourgain, F. A. Grünbaum, L. Velázquez, J. Wilkening
A notion of monitored recurrence for discrete-time quantum processes was recently introduced in [Commun. Math. Phys., DOI 10.1007/s00220-012-1645-2] (see also arXiv:1202.3903) taking the initial state as an absorbing one. We extend this notion of monitored recurrence to absorbing subspaces of arbitrary finite dimension. The generating function approach leads
- Microscopic Mechanism of Stereochemically Active Lone Pair Studied from Orbital Selective External Potential Calculationcond-mat.mtrl-sci
Yongping Du, Hang-Chen Ding, Li Sheng, Sergey Y. Savrasov
The nature of the stereochemically active lone pair has long been in debate. Here, by application of our recently developed orbital selective external potential (OSEP) method, we have studied the microscopic mechanism of stereochemically active lone pairs in various compounds. The OSEP method allows us to shift the energy level of specific atomic orbital, th
Sourav Chatterjee, Frederic A. Rasio, Alison Sills, Evert Glebbeek
Blue straggler stars (BSS) are abundantly observed in all Galactic globular clusters (GGC) where data exist. However, observations alone cannot reveal the relative importance of various formation channels or the typical formation times for this well studied population of anomalous stars. Using a state-of-the-art H\'enon-type Monte Carlo code that includes al
Pedro A. S. Salomão, Joa Weber
Assume M is a closed connected smooth manifold and H:T^*M->R a smooth proper function bounded from below. Suppose the sublevel set {H<d} contains the zero section and \alpha is a non-trivial homotopy class of free loops in M. Then for almost every s>=d the level set {H=s} carries a periodic orbit z of the Hamiltonian system (T^*M,\omega_0,H) representing \al
Larry Denneau, Robert Jedicke, Tommy Grav, Mikael Granvik
We describe the Pan-STARRS Moving Object Processing System (MOPS), a modern software package that produces automatic asteroid discoveries and identifications from catalogs of transient detections from next-generation astronomical survey telescopes. MOPS achieves > 99.5% efficiency in producing orbits from a synthetic but realistic population of asteroids who
Eric F. Lock, David B. Dunson
The task of clustering a set of objects based on multiple sources of data arises in several modern applications. We propose an integrative statistical model that permits a separate clustering of the objects for each data source. These separate clusterings adhere loosely to an overall consensus clustering, and hence they are not independent. We describe a com
- Can active-sterile neutrino oscillations lead to chaotic behavior of the cosmological lepton asymmetry?astro-ph.CO
Steen Hannestad, Rasmus Sloth Hansen, Thomas Tram
While the cosmic baryon asymmetry has been measured at high accuracy to be 6.1*10^-10, a corresponding lepton asymmetry could be as large as 10^-2 if it hides in the neutrino sector. It has been known for some time that a large asymmetry can be generated from a small initial asymmetry given the existence of a sterile neutrino with a mass less than the mass o
Kamil Salikhov, Gustavo Sacomoto, Gregory Kucherov
De Brujin graphs are widely used in bioinformatics for processing next-generation sequencing data. Due to a very large size of NGS datasets, it is essential to represent de Bruijn graphs compactly, and several approaches to this problem have been proposed recently. In this work, we show how to reduce the memory required by the algorithm of [3] that represent
Otti D'Huys, Steffen Zeeb, Thomas Jüngling, Serhiy Yanchuk
We study chaotic systems with multiple time delays that range over several orders of magnitude. We show that the spectrum of Lyapunov exponents (LE) in such systems possesses a hierarchical structure, with different parts scaling with the different delays. This leads to different types of chaos, depending on the scaling of the maximal LE. Our results are rel
Mohammad R. Garousi
Recently, it has been shown that the NS-NS corrections to the type II supergravity given by Gross and Sloan are invariant under the linear T-duality. In this paper, we study the invariance of this action under sequence of S-duality and linear T-duality to find the R-R corrections to the supergravity at order $\alpha'^3$, up to field redefinition.
Alejandro M. Aragón
The last few years have seen the proliferation of measures that quantify the scientific output of researches. Yet, these measures focus on productivity, thus fostering the "publish or perish" paradigm. This article proposes a measure that aims at quantifying the impact of research de-emphasizing productivity, thus providing scientists an alternative, conceiv
Francoise Combes, Alexei Moiseev, Vladimir Reshetnikov
We have searched for CO lines in a sample of 21 new morphologically determined polar-ring galaxies (of which nine are kinematically confirmed), obtained from a wide search in the Galaxy Zoo project by Moiseev and collaborators. Polar-ring galaxies (PRG) are a unique class of objects, tracing special episodes in the galaxy mass assembly: they can be formed th
Srijit Bhattacharjee, Parthasarathi Majumdar
The gauge-dependence of the one loop Coleman-Weinberg effective potential in scalar electrodynamics is resolved using a gauge-free approach not requiring any gauge-fixing of quantum fluctuations of the photon degrees of freedom. This leads to a unique dynamical ratio at one loop of the Higgs mass to the photon mass. We compare our approach and results with t
Glencora Borradaile, Philip Klein, Claire Mathieu
We give a randomized O(n polylog n)-time approximation scheme for the Steiner forest problem in the Euclidean plane. For every fixed eps > 0 and given n terminals in the plane with connection requests between some pairs of terminals, our scheme finds a (1 + eps)-approximation to the minimum-length forest that connects every requested pair of terminals.
Paul de Medeiros, Stefan Hollands
We show how the rigid conformal supersymmetries associated with a certain class of pseudo-Riemannian spin manifolds define a Lie superalgebra. The even part of this superalgebra contains conformal isometries and constant R-symmetries. The odd part is generated by twistor spinors valued in a particular R-symmetry representation. We prove that any manifold whi
Katrin Wolff, Aljoscha M. Hahn, Holger Stark
Self-propelled particles in an external gravitational field have been shown to display both an increased sedimentation length and polar order even without particle interactions. Here, we investigate self-propelled particles which additionally are bottom-heavy, that is they feel a torque aligning them to swim against the gravitational field. For bottom-heavy
Vivek Narayanan, P. J. Morrison
It is shown in this paper how a connection may be made between the symmetry generators of the Hamiltonian (or potential) invariant under a symmetry group $G$, and the subcasimirs that come about when the rank of the Poisson structure of a dynamical system drops by an even integer. This {\em kinematics-dynamics} connection is made by using the algebraic geome
- Coherence creation in an optically thick medium by matched propagation of a chirped laser pulse pairquant-ph
N. Sandor, G. Demeter, D. Dzsotjan, G. P. Djotyan
We consider the simultaneous propagation of a pair of Raman-resonant, frequency-modulated (chirped) laser pulses in an optically thick medium, modeled by an ensemble of $\Lambda$-atoms. A self-organization ('matching`) effect is shown for the chirped pulse pair, which leads to a quasi-lossless propagation. Furthermore, we demonstrate that a well-defined cohe
Valter Pohjola
In this paper we prove uniqueness for an inverse boundary value problem for the magnetic Schr\"odinger equation in a half space, with partial data. We prove that the curl of the magnetic potential $A$, when $A\in W_{comp}^{1,\infty}(\ov{\R^3_{-}},\R^3)$, and the electric pontetial $q \in L_{comp}^{\infty}(\ov{\R^3_{-}},\C)$ are uniquely determined by the kno