August 2010 arXiv papers — page 23
Showing 2,201–2,300 of 5,306 papers
Przemyslaw Bienias, Krzysztof Pawlowski, Mariusz Gajda, Kazimierz Rzazewski
Monte Carlo method within, so called, classical fields approximation is applied to one dimensional weakly interacting repulsive Bose gas trapped in a harmonic potential. Equilibrium statistical properties of the condensate are calculated within a canonical ensemble. We also calculate experimentally relevant low order correlation functions of the whole gas.
Elsenhans, Andreas-Stephan
We searched up to height $10^7$ for rational points on diagonal quartic surfaces. The computations fill several gaps in earlier lists computed by Pinch, Swinnerton-Dyer, and Bright.
Sharp three sphere inequality for perturbations of a product of two second order elliptic operators and stability for the Cauchy problem for the anisotropic plate equation
math.APAntonino Morassi, Edi Rosset, Sergio Vessella
We prove a sharp three sphere inequality for solutions to third order perturbations of a product of two second order elliptic operators with real coefficients. Then we derive various kinds of quantitative estimates of unique continuation for the anisotropic plate equation. Among these, we prove a stability estimate for the Cauchy problem for such an equation
A doubled double hotspot in J0816+5003 and the logarithmic slope of the lensing potential
astro-ph.COKatherine Blundell, Paul Schechter, Nick Morgan, Matt Jarvis
We present an analysis of observations of the doubly-lensed double hotspot in the giant radio galaxy J0816+5003 from MERLIN, MDM, WIYN, WHT, UKIRT and the VLA. The images of the two hotspot components span a factor of two in radius on one side of the lensing galaxy at impact parameters of less than 500pc. Hence we measure the slope of the lensing potential o
Stanislav Shkarin
We construct an infinite dimensional non-unital Banach algebra $A$ and $a\in A$ such that the sets $\{za^n:z\in\C,\ n\in\N\}$ and $\{({\bf 1}+a)^na:n\in\N\}$ are both dense in $A$, where $\bf 1$ is the unity in the unitalization $A^{\#}=A\oplus \spann\{{\bf 1}\}$ of $A$. As a byproduct, we get a hypercyclic operator $T$ on a Banach space such that $T\oplus T
Alexey Galda, Igor V. Yurkevich, Igor V. Lerner
We study the influence of electron-phonon coupling on electron transport through a Luttinger liquid with an embedded weak scatterer or weak link. We derive the renormalization group (RG) equations which indicate that the directions of RG flows can change upon varying either the relative strength of the electron-electron and electron-phonon coupling or the ra
The vortex pinning on the cylindrical defects and the electronic structure of the vortex core
cond-mat.supr-conV. L. Kulinskii, D. Yu. Panchenko
The model of the Abrikosov vortex pinning on a cylindrical defect is proposed. It is shown that in the limit $\varkappa \gg 1$ the potential for the vortex core excitations can be treated in terms of the zero-range potentials method. Using the variational method the estimates for the energy of pinning, the pinning force and the density of critical current de
An investigation of the discriminant power and dimensionality of items used for assessing health condition of elderly people
stat.APFrancesco Bartolucci, Giorgio d'Agostino, Giorgio E. Montanari
With reference to the questionnaire adopted within the Italian project "Ulisse" to assess health condition of elderly people, we investigate two important issues: discriminant power and actual number of dimensions measured by the items composing the questionnaire. The adopted statistical approach is based on the joint use of the latent class model an
Stanislav Shkarin
Bonet, Frerick, Peris and Wengenroth constructed a hypercyclic operator on the locally convex direct sum of countably many copies of the Banach space $\ell_1$. We extend this result. In particular, we show that there is a hypercyclic operator on the locally convex direct sum of a sequence $\{X_n\}_{n\in\N}$ of Fréchet spaces if and only if each $X_n$ is sepa
Paul Johnson
We derive an algorithm to produce explicit formulas for certain generating functions of double Hurwitz numbers. These formulas generalize a formula of Goulden, Jackson and Vakil for one part double Hurwitz numbers. Immediate consequences include a new proof that double Hurwitz numbers are piecewise polynomial, an understanding of the chamber structure and wa
Vladimir Dzhunushaliev
Stochastic Einstein equations are considered when 3D space metric $γ_{ij}$ are stochastic functions. The probability density for the stochastic quantities is connected with the Perelman's entropy functional. As an example, the Friedman Universe is considered. It is shown that for the Friedman Universe the dynamical evolution is not changed. The connectio
Higher Dimensional Homology Algebra IV:Projective Resolutions and Derived 2-Functors in ($\cR$-2-Mod)
math.CTFang Huang, Shao-Han Chen, Wei Chen, Zhu-Jun Zheng
In this paper, we will construct the projective resolution of any $\cR$-2-module, define the derived 2-functor and give some related properties of the derived 2-functor.
Multiple Conceptual Coherences in the Speed Tutorial: Micro-processes of Local Stability
physics.ed-phBrian W. Frank
Researchers working within knowledge-in-pieces traditions have often employed observational approaches to investigate micro-processes of learning. There is growing evidence from this line of work that students' intuitive thinking about physical phenomena is characterized more so by its diversity and flexibility than its uniformity and robustness. This ch
The effect of density stratification on the resonant absorption of MHD waves in coronal loops
astro-ph.SRK. Karami, S. Nasiri, S. Amiri
The standing quasi-modes of the ideal MHD in a zero-$β$ cylindrical magnetic flux tube that undergoes a longitudinal density stratification and radial density structuring is considered. The radial structuring is assumed to be a linearly varying density profile. Using the relevant connection formulae of the resonant absorption, the dispersion relation for the
J. W. González, H. Santos, E. Prada, L. Brey
We study the conductance of a biased bilayer graphene flake with monolayer nanoribbon contacts. We find that the transmission through the bilayer ribbon strongly depends on the applied bias between the two layers and on the relative position of the monolayer contacts. Besides the opening of an energy gap on the bilayer, the bias allows to tune the electronic
Gain of the kinetic energy of bipolarons in the t-J-Holstein model based on electron-phonon coupling
cond-mat.str-elLev Vidmar, Janez Bonca
With increasing electron-phonon coupling as described within the t-J-Holstein model, bipolaron kinetic energy is lowered in comparison with that of the polaron. This effect is accompanied with "undressing" of bipolaron from lattice degrees of freedom. Consequently, the effective bipolaron mass becomes smaller than the polaron mass. Magnetic as well a
Andreas U. Schmidt, Andreas Leicher, Yogendra Shah, Inhyok Cha
We define secure operations with tree-formed, protected verification data registers. Functionality is conceptually added to Trusted Platform Modules (TPMs) to handle Platform Configuration Registers (PCRs) which represent roots of hash trees protecting the integrity of tree-formed Stored Measurement Logs (SMLs). This enables verification and update of an inn
On the reduction of PDE's problems in the half-space, under the slip boundary condition, to the corresponding problems in the whole space
math.APH. Beirão da Veiga, F. Crispo, C. R. Grisanti
The resolution of a very large class of linear and non-linear, stationary and evolutive partial differential problems in the half-space (or similar) under the slip boundary condition is reduced here to that of the corresponding results for the same problem in the whole space. The approach is particularly suitable for proving new results in strong norms. To d
Thomas Foertsch, Viktor Schroeder
In this paper we characterize compact extended Ptolemy metric spaces with many circles up to Möbius equivalence. This characterization yields a Möbius characterization of the $n$-dimensional spheres $S^n$ and hemispheres $S^n_+$ when endowed with their chordal metrics. In particular, we show that every compact extended Ptolemy metric space with the property
Jana Vejpravová-Poltierová, Jiří Pospíšil, Jan Prokleška, Karel Prokeš
We propose an alternate scenario for the relation between ferromagnetism (FM) and superconductivity (SC) in UCoGe at ambient pressure. On the basis of neutron polarimetry measurement performed in strictly zero field on a single-crystal at ambient pressure, we claim that the SC phase does exist in spite of lack of long-range FM order. Moreover, the SC regime
Abel Castoreña, Ciro Ciliberto
In this paper we prove a theorem stated by Castelnuovo which bounds the dimension of linear systems of plane curves in terms of two invariants, one of which is the genus of the curves in the system. Then we classify linear systems whose dimension belongs to certain intervals which naturally arise from Castelnuovo's theorem. Finally we make an application
Emergence of states in the phonon spectral function of the Holstein polaron below and above the one-phonon continuum
cond-mat.otherLev Vidmar, Janez Bonca, Stuart A. Trugman
We investigate the low-energy properties of the Holstein polaron through calculation of the q-dependent phonon spectral function using an improved exact-diagonalization technique, defined over a variational Hilbert space. We perform a comprehensive study of the low-energy excitations of the polaron. Beside the energy range, where the additional phonon excita
D. Stauffer, S. Cebrat, T. J. P. Penna, A. O. Sousa
The standard Penna ageing model with sexual reproduction is enlarged by adding additional bit-strings for love: Marriage happens only if the male love strings are sufficiently different from the female ones. We simulate at what level of required difference the population dies out.
Wang Bo-Qun, Mo Xiao-Hu, Wang Ping, Ban Yong
It has been conjectured that the relative phase between strong and electromagnetic amplitudes is universally $-90^{\circ}$ in charmonium decays. $ψ^{\prime}$ decaying into pseudoscalar pair provides a possibility to test this conjecture. However, the experimentally observed cross section for such a process is depicted by the two-fold integral which takes int
Jude Prezens
For over 25 years, a solution has existed to Einstein's vacuum equation that describes a space-time with two Kerr black holes. First formulated by Kramer and Neugebauer (KN) in 1980 [1], this solution has been extensively researched by many, with many and varied implications. One of which is causality violation.
Roberto Emparan, Pau Figueras
Configurations of multiple concentric black rings play an important role in determining the pattern of branchings, connections and mergers between different phases of higher-dimensional black holes. We examine them using both approximate and (in five dimensions) exact methods. By identifying the role of the different scales in the system, we argue that it is
N. Ghroda
A subsemigroup $S$ of an inverse semigroup $Q$ is a left I-order in $Q$ if every element in $Q$ can be written as $a^{-1}b$ where $a,b \in S$ and $a^{-1}$ is the inverse of $a$ in the sense of inverse semigroup theory. If we insist on $a$ and $b$ being $\mathcal{R}$-related in $Q$, then we say that $S$ is a straight left I-order in $Q$. We give necessary and
I. -J. Kim, K. -I. Seon, K. -W. Min, J. -H. Shinn
We present the first far-ultraviolet (FUV) emission-line morphologies of the whole region of the supernova remnant (SNR) G65.3+5.7 using the FIMS/SPEAR data. The morphologies of the C IV λλ1548, 1551, He II λ1640, and O III] λλ1661, 1666 lines appear to be closely related to the optical and/or soft X-ray images obtained in previous studies. Dramatic differen
Non-LTE time-dependent spectroscopic modelling of type II-plateau supernovae from the photospheric to the nebular phase: case study for 15 and 25Msun progenitor stars
astro-ph.SRLuc Dessart, D. John Hillier
We present the first non-LTE time-dependent radiative-transfer simulations of supernovae (SNe) II-Plateau (II-P) covering both the photospheric and nebular phases, from ~10 to >~1000d after the explosion, and based on 1.2B piston-driven ejecta produced from a 15Msun and a 25Msun non-rotating solar-metallicity star. The radial expansion of the gradually cooli
Fumitoshi Amemiya, Tatsuhiko Koike
A gauge-invariant quantum theory of the Friedmann-Robertson-Walker (FRW) universe with dust is studied in terms of the Ashtekar variables. We use the reduced phase space quantization which has following advantages: (i) fundamental variables are all gauge invariant, (ii) there exists a physical time evolution of gauge-invariant quantities, so that the problem
Effect of LaAlO3 twin-domain topology on local dc and microwave properties of cuprate films
cond-mat.supr-conA. P. Zhuravel, Steven M. Anlage, Stephen K. Remillard, A. V. Lukashenko
Different imaging modes of low temperature laser scanning microscopy (LTLSM) have been applied to probe local optical and superconducting properties, as well as the spatial variations in thermoelectric and electronic (both dc and rf) transport, in a YBa_2Cu_3O_6.95 /LaAlO_3 (YBCO/LAO) superconducting microstrip resonator with micron-range resolution. Additio
Sapam Ranjita Chanu, Alok K. Singh, Boris Brun, Kanhaiya Pandey
We observe linewidths below the natural linewidth for a probe laser on a {\it two-level system}, when the same transition is driven by a strong control laser. We take advantage of the fact that each level is made of multiple magnetic sublevels, and use the phenomenon of electromagnetically induced transparency or absorption in multilevel systems. Optical pum
Empirical Likelihood based Confidence Regions for first order parameters of a heavy tailed distribution
math.STJulien Worms, Rym Worms
Let $X_1, \ldots, X_n$ be some i.i.d. observations from a heavy tailed distribution $F$, i.e. such that the common distribution of the excesses over a high threshold $u_n$ can be approximated by a Generalized Pareto Distribution $G_{γ,σ_n}$ with $γ>0$. This work is devoted to the problem of finding confidence regions for the couple $(γ,σ_n)$ : combining the
Precise measurement of hyperfine structure in the ${2P}_{1/2}$ state of $^{7}$Li using saturated-absorption spectroscopy
physics.atom-phAlok K. Singh, Lal Muanzuala, Vasant Natarajan
We report a precise measurement of the hyperfine interval in the ${2P}_{1/2}$ state of $^{7}$Li. The transition from the ground state ($D_1$ line) is accessed using a diode laser and the technique of saturated-absorption spectroscopy in hot Li vapor. The interval is measured by locking an acousto-optic modulator to the frequency difference between the two hy
Role of population transfer under strong probe conditions in electromagnetically induced transparency
physics.opticsKanhaiya Pandey, Dipankar Kaundilya, Vasant Natarajan
We analyze theoretically the phenomenon of electromagnetically induced transparency (EIT) under conditions where the probe laser is not in the usual weak limit. We consider the effects in both three-level and four-level systems, which are either closed or open (due to losses to an external metastable level). We find that the EIT dip almost disappears in a cl
T. Lappi
The physics of the initial conditions of heavy ion collisions is dominated by the nonlinear gluonic interactions of QCD. These lead to the concepts of parton saturation and the Color Glass Condensate (CGC). We discuss recent progress in calculating multi-gluon correlations in this framework, prompted by the observation that these correlations are in fact eas
J. A. Aguilar-Saavedra
Top interactions beyond the Standard Model can be conveniently described in the framework of gauge-invariant effective operators. We briefly review the general form of the fermion-fermion-gauge boson and fermion-fermion-Higgs interactions arising from dimension-6 operators, focusing on the top quark. We discuss in detail an expansion in powers of 1/Lambda^2,
Kanhaiya Pandey, K. D. Rathod, Alok K. Singh, Vasant Natarajan
We demonstrate launching of laser-cooled Yb atoms in a cold atomic fountain. Atoms in a collimated thermal beam are first cooled and captured in a magneto-optic trap (MOT) operating on the strongly-allowed ${^1S}_0 \rightarrow {^1P}_1$ transition at 399~nm (blue line). They are then transferred to a MOT on the weakly-allowed ${^1S}_0 \rightarrow {^3P}_1$ tra
Johannes Skaar
The concepts of negative refractive index and near-field imaging are explained in the form of a tutorial.
Christoffer Sloth, Rafael Wisniewski
In this report proofs are presented for a method for abstracting continuous dynamical systems by timed automata. The method is based on partitioning the state space of dynamical systems with invariant sets, which form cells representing locations of the timed automata. To enable verification of the dynamical system based on the abstraction, conditions for ob
Rainer Buckdahn, Ingo Bulla, Jin Ma
In this paper we study the {\it pathwise stochastic Taylor expansion}, in the sense of our previous work \cite{Buckdahn_Ma_02}, for a class of Itô-type random fields in which the diffusion part is allowed to contain both the random field itself and its spatial derivatives. Random fields of such an "self-exciting" type particularly contains the fully
Jouko Mickelsson
Twisted K-theory classes over compact Lie groups can be realized as families of Fredholm operators using the representation theory of loop groups. In this talk I want to show how to deform the Fredholm family, in the sense of quantum groups. The family of Dirac type operators is parametrized by vectors in the adjoint module for a quantum affine algebra and t
Limited influence of diluted ferromagnetic dimers on Curie temperature in complex magnetic systems
cond-mat.str-elM. V. Medvedev, I. A. Nekrasov
In this work we investigate Ising and classical Heisenberg models for two and three dimensional lattices in presence of diluted ferromagnetic dimers. For such models the Curie temperature as a function of ratio of intra-dimer exchange coupling constant I_A and other inter-site coupling constants I_B is calculated. In case dimer is treated exactly and environ
K. Kanaya, S. Aoki, S. Ejiri, T. Hatsuda
The WHOT-QCD Collaboration is pushing forward lattice studies of QCD at finite temperatures and densities using improved Wilson quarks. We first present results on QCD at zero and finite densities with two flavors of degenerate quarks (N_F=2 QCD) adopting the conventional fixed-Nt approach. We then report on the status of a study of N_F=2+1 QCD adopting a fi
Saeed Akbari, Sadegh Bolouki, Pooya Hatami, Milad Siami
Let $γ'_s(G)$ be the signed edge domination number of G. In 2006, Xu conjectured that: for any $2$-connected graph G of order $ n (n \geq 2),$ $γ'_s(G)\geq 1$. In this article we show that this conjecture is not true. More precisely, we show that for any positive integer $m$, there exists an $m$-connected graph $G$ such that $ γ'_s(G)\leq -\frac{
Pooya Hatami
We introduce a $2$-approximation algorithm for the minimum total covering number problem.
Johan Anderson, Pavlos Xanthopoulos
This Letter provides a theoretical interpretation of numerically generated probability density functions (PDFs) of intermittent plasma transport events. Specifically, nonlinear gyrokinetic simulations of ion-temperature-gradient turbulence produce time series of heat flux which exhibit manifestly non-Gaussian PDFs with enhanced tails. It is demonstrated that
Babak Behsaz, Pooya Hatami
In this note, we study the behavior of independent sets of maximum probability measure in tensor graph powers. To do this, we introduce an upper bound using measure preserving homomorphisms. This work extends some previous results about independence ratios of tensor graph powers.
Chilin V. I., Muminov K. K
It is shown that every nonsingular continuous representation of the group algebra $L^{1}(G)$ in Banach spaces is completely reducible if and only if $G$ is a compact group.
A. F. Ber, F. A. Sukochev
Let $\mathcal{M}$ be a $W^*$-factor and let $S\left( \mathcal{M} \right) $ be the space of all measurable operators affiliated with $\mathcal{M}$. It is shown that for any self-adjoint element $a\in S(\mathcal{M})$ there exists a scalar $λ_0\in\mathbb{R}$, such that for all $\varepsilon > 0$, there exists a unitary element $u_\varepsilon$ from $\mathcal{M}$,
Wei Han, K. Pi, K. M. McCreary, Yan Li
We achieve tunneling spin injection from Co into single layer graphene (SLG) using TiO2 seeded MgO barriers. A non-local magnetoresistance (ΔRNL) of 130 Ω is observed at room temperature, which is the largest value observed in any material. Investigating ΔRNL vs. SLG conductivity from the transparent to the tunneling contact regimes demonstrates the contrast
Babak Behsaz, Pooya Hatami, Ebadollah S. Mahmoodian
For natural numbers $n$ and $k$ ($n > 2k$), a generalized Petersen graph $P(n,k)$, is defined by vertex set $\lbrace u_i,v_i\rbrace$ and edge set $\lbrace u_iu_{i+1},u_iv_i,v_iv_{i+k}\rbrace$; where $i = 1,2,\dots,n$ and subscripts are reduced modulo $n$. Here first, we characterize minimum vertex covers in generalized Petersen graphs. Second, we present a l
Christophe Royon
We describe the ATLAS Forward Physics Program at low luminosity using the rapidity gap method and a dedicated detector called ALFA to tag the protons. We also describe the physics topics of the ATLAS Forward Physics Project at high instantaneous luminosity.
Ulrich Wurstbauer, Christian Röling, Ursula Wurstbauer, Werner Wegscheider
Imaging ellipsometry studies of graphene on SiO2/Si and crystalline GaAs are presented. We demonstrate that imaging ellipsometry is a powerful tool to detect and characterize graphene on any flat substrate. Variable angle spectroscopic ellipsometry is used to explore the dispersion of the optical constants of graphene in the visible range with high lateral r
Murat Kologlu, Gene Kopp, Steven J. Miller, Yinghui Wang
Zeckendorf proved that every positive integer has a unique representation as a sum of non-consecutive Fibonacci numbers. Once this has been shown, it's natural to ask how many summands are needed. Using a continued fraction approach, Lekkerkerker proved that the average number of such summands needed for integers in $[F_n, F_{n+1})$ is $n / (φ^2 + 1) + O
Jeremiah Buckley, Xavier Massaneda, Joaquim Ortega-Cerdà
Following a scheme of Levin we describe the values that functions in Fock spaces take on lattices of critical density in terms of both the size of the values and a cancelation condition that involves discrete versions of the Cauchy and Beurling-Ahlfors transforms.
General Auction-Theoretic Strategies for Distributed Partner Selection in Cooperative Wireless Networks
cs.ITAmitav Mukherjee, Hyuck Kwon
It is unrealistic to assume that all nodes in an ad hoc wireless network would be willing to participate in cooperative communication, especially if their desired Quality-of- Service (QoS) is achievable via direct transmission. An incentivebased auction mechanism is presented to induce cooperative behavior in wireless networks with emphasis on users with asy
Don Torrieri, Amitav Mukherjee, Hyuck Kwon
In this paper, we describe direct-sequence code-division multiple-access (DS-CDMA) systems with quadriphase-shift keying in which channel estimation, coherent demodulation, and decoding are iteratively performed without the use of any training or pilot symbols. An expectation-maximization channel-estimation algorithm for the fading amplitude, phase, and the
Krishna Mohan Gundu, Parisa Gandomkar Yarandi, Arash Mafi
The beam quality factor M^2 for the fundamental LP01 mode of a step-index fiber is calculated in the presence of gain, in a closed form, as a function of the complex generalized V-number. It is shown that the M^2 value of a single-mode gain-guided fiber laser can be arbitrary large. The results are important for the interpretation of the beam quality measure
Ferran Hurtado, Giuseppe Liotta, David R. Wood
A drawing of a given (abstract) tree that is a minimum spanning tree of the vertex set is considered aesthetically pleasing. However, such a drawing can only exist if the tree has maximum degree at most 6. What can be said for trees of higher degree? We approach this question by supposing that a partition or covering of the tree by subtrees of bounded degree
David R. Wood
This paper addresses the following questions for a given tree $T$ and integer $d\geq2$: (1) What is the minimum number of degree-$d$ subtrees that partition $E(T)$? (2) What is the minimum number of degree-$d$ subtrees that cover $E(T)$? We answer the first question by providing an explicit formula for the minimum number of subtrees, and we describe a linear
Gabriel R. Bengochea
In the present work we analyze and compare the information coming from different observational data sets in the context of a sort of f(T) theories. We perform a joint analysis with measurements of the most recent type Ia supernovae (SNe Ia), Baryon Acoustic Oscillation (BAO), Cosmic Microwave Background radiation (CMB), Gamma-Ray Bursts data (GRBs) and Hubbl
Diana Nicmorus, Gernot Eichmann, Reinhard Alkofer
We investigate the electromagnetic form factors of the Delta and the Omega baryons within the Poincare-covariant framework of Dyson-Schwinger and Bethe-Salpeter equations. The three-quark core contributions of the form factors are evaluated by employing a quark-diquark approximation. We use a consistent setup for the quark-gluon dressing, the quark-quark bou
Yan He, C. M. Varma
We show that the two branches of collective modes discovered recently in under-doped Cuprates with huge spectral weight are a necessary consequence of the loop-current state. Such a state has been shown in earlier experiments to be consistent with the symmetry of the order parameter competing with superconductivity in four families of Cuprates. We also predi
Rodrigo Bufalo, Bruto Max Pimentel, German Enrique Ramos Zambrano
In this paper, a complete covariant quantization of generalized electrodynamics is shown through the path integral approach. To this goal, we first studied the hamiltonian structure of system following Dirac's methodology and, then, we followed the Faddeev-Senjanovic procedure to obtain the transition amplitude. The complete propagators (Schwinger-Dyson-
Yosuke Imamura, Shuichi Yokoyama
We study Kaluza-Klein modes of a d=7, N=2 vector multiplet in AdS_4 x S^3. Such modes arise in the context of AdS/CFT as dual objects of a class of gauge invariant operators in N=4 Chern-Simons theories. We confirm that the Kaluza-Klein modes precisely reproduce the BPS spectrum of the operators.
Measuring the 3D Clustering of Undetected Galaxies Through Cross Correlation of their Cumulative Flux Fluctuations from Multiple Spectral Lines
astro-ph.COEli Visbal, Abraham Loeb
We discuss a method for detecting the emission from high redshift galaxies by cross correlating flux fluctuations from multiple spectral lines. If one can fit and subtract away the continuum emission with a smooth function of frequency, the remaining signal contains fluctuations of flux with frequency and angle from line emitting galaxies. Over a particular
J. David Brown
An action principle for the generalized harmonic formulation of general relativity is presented. The action is a functional of the spacetime metric and the gauge source vector. An action principle for the Z4 formulation of general relativity has been proposed recently by Bona, Bona--Casas and Palenzuela (BBP). The relationship between the generalized harmoni
K. Azizi, R. Khosravi, F. Falahati
We analyze the rare semileptonic $B_s \to (η, η') l^+ l^-$, $(l=e, μ, τ)$ and $B_s \to (η, η') ν\barν$ transitions probing the $\bar s s$ content of the $η$ and $η'$ mesons via three--point QCD sum rules. We calculate responsible form factors for these transitions in full theory. Using the obtained form factors, we also estimate the related branc
Tsz-Wo Sze
We present a new record on computing specific bits of Pi, the mathematical constant, and discuss performing such computations on Apache Hadoop clusters. The specific bits represented in hexadecimal are 0E6C1294 AED40403 F56D2D76 4026265B CA98511D 0FCFFAA1 0F4D28B1 BB5392B8. These 256 bits end at the 2,000,000,000,000,252nd bit position, which doubles the pos
Cristian Danescu-Niculescu-Mizil, Lillian Lee
Researchers in textual entailment have begun to consider inferences involving 'downward-entailing operators', an interesting and important class of lexical items that change the way inferences are made. Recent work proposed a method for learning English downward-entailing operators that requires access to a high-quality collection of 'negative po
Jason L. Evans, Matthew Sudano, Tsutomu T. Yanagida
We construct a model that naturally generates mu and B of the same order without producing large CP violating phases. This is easily accomplished once one permits these mass scales to be determined independently of the ordinary gauge-mediated soft masses. The alignment of phases is shown to emerge dynamically upon coupling to supergravity and is not unique t
Tomas Boothby, Allison Henrich, Alexander Leaf
Manturov recently introduced the idea of a free knot, i.e. an equivalence class of virtual knots where equivalence is generated by crossing change and virtualization moves. He showed that if a free knot diagram is associated to a graph that is irreducibly odd, then it is minimal with respect to the number of classical crossings. Not all minimal diagrams of f
Valentin Ahrens, Thomas Becher, Matthias Neubert, Li Lin Yang
We present updated predictions for the total cross section for Higgs boson production through gluon fusion at hadron colliders. In addition to renormalization-group improvement at next-to-next-to-next-to-leading logarithmic accuracy, we incorporate the two-loop electroweak corrections, which leads to the most precise predictions at present. Numerical results
David J. Mulryne, David Seery, Daniel Wesley
In a recent publication, we proposed that inflationary perturbation theory can be reformulated in terms of a probability transport equation, whose moments determine the correlation properties of the primordial curvature perturbation. In this paper we generalize this formulation to an arbitrary number of fields. We deduce ordinary differential equations for t
Stefan Meinel
The mass of the triply heavy baryon Omega_bbb is calculated in lattice QCD with 2+1 flavors of light sea quarks. The b quark is implemented with improved lattice NRQCD. Gauge field ensembles from both the RBC/UKQCD and MILC collaborations with lattice spacings in the range from 0.08 fm to 0.12 fm are used. The final result for the Omega_bbb mass, which inclu
Statistical mechanics of transcription-factor binding site discovery using Hidden Markov Models
cond-mat.stat-mechPankaj Mehta, David Schwab, Anirvan M. Sengupta
Hidden Markov Models (HMMs) are a commonly used tool for inference of transcription factor (TF) binding sites from DNA sequence data. We exploit the mathematical equivalence between HMMs for TF binding and the "inverse" statistical mechanics of hard rods in a one-dimensional disordered potential to investigate learning in HMMs. We derive analytic exp
J. S. Urquhart, T. J. T. Moore, M. G. Hoare, S. L. Lumsden
The Red MSX Source (RMS) survey has identified a large sample of massive young stellar objects (MYSOs) and ultra compact (UC) HII regions from a sample of ~2000 MSX and 2MASS colour selected sources. Using a recent catalogue of molecular clouds derived from the Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey (GRS), and by appl
Evolution of Spin Direction of Accreting Magnetic Protostars and Spin-Orbit Misalignment in Exoplanetary Systems
astro-ph.EPDong Lai, Francois Foucart, Douglas N. C. Lin
Recent observations have shown that in many exoplanetary systems the spin axis of the parent star is misaligned with the planet's orbital axis. These have been used to argue against the scenario that short-period planets migrated to their present-day locations due to tidal interactions with their natal discs. However, this interpretation is based on the
Albert Fannjiang
This paper studies the problem of exact localization of sparse (point or extended) objects with noisy data. The crux of the proposed approach consists of random illumination. Several recovery methods are analyzed: the Lasso, BPDN and the One-Step Thresholding (OST). For independent random probes, it is shown that both recovery methods can localize exactly $s
Steve Awodey, Henrik Forssell
From a logical point of view, Stone duality for Boolean algebras relates theories in classical propositional logic and their collections of models. The theories can be seen as presentations of Boolean algebras, and the collections of models can be topologized in such a way that the theory can be recovered from its space of models. The situation can be cast a
Tian-Min Yan, S. V. Popruzhenko, M. J. J. Vrakking, D. Bauer
Experiments on atoms in intense laser pulses and the corresponding exact ab initio solutions of the time-dependent Schr\"odinger equation (TDSE) yield photoelectron spectra with low-energy features that are not reproduced by the otherwise successful work horse of strong field laser physics: the "strong field approximation" (SFA). In the semi-classical limit,
Nathaniel R. Butler, Joshua S. Bloom
We present a novel method for the optimal selection of quasars using time-series observations in a single photometric bandpass. Utilizing the damped random walk model of Kelly et al. (2009), we parameterize the ensemble quasar structure function in Sloan Stripe 82 as a function of observed brightness. The ensemble model fit can then be evaluated rigorously f
D^0 -> gamma gamma and D^0 -> mu^+ mu^- Rates on an Unlikely Impact of the Littlest Higgs Model with T-Parity
hep-phAyan Paul, Ikaros I. Bigi, Stefan Recksiegel
The decays D^0 -> gamma gamma, $mu^+ mu^- are highly suppressed in the Standard Model (SM) with the lion's share of the rate coming from long distance dynamics; D^0 -> mu^+ mu^- is driven predominantly by D^0 -> gamma gamma -> mu^+ mu^-. Their present experimental bounds are small, yet much larger than SM predictions. New Physics models like the Littlest
The Poisson algebra of classical Hamiltonians in field theory and the problem of its quantization
math-phA. Stoyanovsky
We construct the commutative Poisson algebra of classical Hamiltonians in field theory. We pose the problem of quantization of this Poisson algebra. We also make some interesting computations in the known quadratic part of the quantum algebra.
The Fate of the Initial State Fluctuations in Heavy Ion Collisions. II The Fluctuations and Sounds
nucl-thPilar Staig, Edward Shuryak
Heavy ion collisions at RHIC are well described by the (nearly ideal) hydrodynamics for average events. In the present paper we study initial state fluctuations appearing on event-by-event basis, and the propagation of perturbations induced by them. We found that (i) fluctuations of several lowest harmonics have comparable magnitudes, (ii) that at least all
New Gauge Field from Extension of Space Time Parallel Transport of Vector Spaces to the Underlying Number Systems
quant-phPaul Benioff
One way of describing gauge theories in physics is to assign a vector space $V_{x}$ to each space time point $x.$ For each $x$ the field $ψ$ takes values $ψ(x)$ in $V_{x}.$ The freedom to choose a basis in each $V_{x}$ introduces gauge group operators and their Lie algebra representations to define parallel transformations between vector spaces. This paper i
Stefan Rotter, Philipp Ambichl, Florian Libisch
We introduce a procedure to generate scattering states which display trajectory-like wave function patterns in wave transport through complex scatterers. These deterministic scattering states feature the dual property of being eigenstates to the Wigner-Smith time-delay matrix and to the transmission matrix with classical (noiseless) transmission eigenvalues
Nasrin Akhter, Kaniz Fatema, Lilatul Ferdouse, Faria Khandaker
The LMS algorithm is one of the most successful adaptive filtering algorithms. It uses the instantaneous value of the square of the error signal as an estimate of the mean-square error (MSE). The LMS algorithm changes (adapts) the filter tap weights so that the error signal is minimized in the mean square sense. In Trigonometric LMS (TLMS) and Hyperbolic LMS
Hadi Godazgar, Malcolm J. Perry
It is known that the transformations of fermionic T-duality, derived from the worldsheet theory, generically transform real supergravity backgrounds to complex supergravity backgrounds. We consider the low-energy target space theory and show that the type II supergravity equations admit a symmetry that transforms the Ramond-Ramond fields and the dilaton. The
Quantitative Excited State Spectroscopy of a Single InGaAs Quantum Dot Molecule through Multi-million Atom Electronic Structure Calculations
cond-mat.mes-hallMuhammad Usman, Yui-Hong Matthias Tan, Hoon Ryu, Shaikh S. Ahmed
Atomistic electronic structure calculations are performed to study the coherent inter-dot couplings of the electronic states in a single InGaAs quantum dot molecule. The experimentally observed excitonic spectrum [12] is quantitatively reproduced, and the correct energy states are identified based on a previously validated atomistic tight binding model. The
H. -B. Yang, J. D. Rameau, Z. -H. Pan, G. D. Gu
The Fermi surface topologies of underdoped samples the high-Tc superconductor Bi2212 have been measured with angle resolved photoemission. By examining thermally excited states above the Fermi level, we show that the Fermi surfaces in the pseudogap phase of underdoped samples are actually composed of fully enclosed hole pockets. The spectral weight of these
Zhi-Feng Sun, Jie-Sheng Yu, Xiang Liu, Takayuki Matsuki
We study three newly observed D(2550), D(2610), and D(2760) by the BaBar Collaboration utilizing the mass spectra and investigating the strong decays. Our calculation indicates that D(2610) is an admixture of $2^3S_1$ and $1^3D_1$ with $J^P=1^-$. $D(2760)$ can be explained as either the orthogonal partner of D(2610) or $1^3D_3$. Our estimate of the decay wid
Abdelmalek Abdesselam, Jaydeep Chipalkatti
There is a classical geometric construction which uses a binary quadratic form to define an involution on the space of binary d-ics. We give a complete characterization of a general class of such involutions which are definable using compound transvectant formulae. We also study the associated varieties of forms which are preserved by such involutions. Along
Pietro Colangelo, Floriana Giannuzzi, Stefano Nicotri
We use gauge/string duality to investigate the free energy of two static color sources (a heavy quark-antiquark pair) in a Yang-Mills theory in strongly interacting matter, varying temperature and chemical potential. The dual space geometry is Anti-de Sitter with a charged black-hole to describe finite temperature and density in the boundary theory, and we a
Maxim Dvornikov
Spin-flavor oscillations of Dirac neutrinos in matter and a magnetic field are studied using the method of relativistic quantum mechanics. Using the exact solution of the wave equation for a massive neutrino, taking into account external fields, the effective Hamiltonian governing neutrino spin-flavor oscillations is derived. Then the The consistency of our
Peter K. F. Kuhfittig
This paper discusses the stability to linearized radial perturbations of spherically symmetric thin-shell wormholes with a "phantom-like" equation of state for the exotic matter at the throat: $P=ωσ$, $ω<0$, where $σ$ is the energy-density of the shell and $P$ the surface pressure. This equation is analogous to the generalized Chaplygin-gas equation
Mathew Bullimore
The action of inverse soft factors on scattering amplitudes in N=4 SYM is shown to take a remarkably simple form in momentum twistor space. This is used to identify individual residues of the grassmannian with primitive leading singularities at NMHV and N^2MHV and to derive explicit expressions in terms of momentum twistors.
J. de Plaa, N. Werner, A. Simionescu, J. S. Kaastra
The physics of the coolest phases in the hot Intra-Cluster Medium (ICM) of clusters of galaxies is yet to be fully unveiled. X-ray cavities blown by the central Active Galactic Nucleus (AGN) contain enough energy to heat the surrounding gas and stop cooling, but locally blobs or filaments of gas appear to be able to cool to low temperatures of 10^4 K. In X-r
Arnaud Beauville
Let X be a holomorphic symplectic manifold, of dimension divisible by 4, and s an antisymplectic involution of X . The fixed locus F of s is a Lagrangian submanifold of X ; we show that its Â-genus is 1. As an application, we determine all possibilities for the Chern numbers of F when X is a deformation of the Hilbert square of a K3 surface.