32
32

Sep 19, 2013
09/13

by
C. Chen; M. Jura

texts

######
eye 32

######
favorite 0

######
comment 0

Using the Keck I telescope, we have obtained 11.7 micron and 18.7 micron images of the circumstellar dust emission from AB Aur, a Herbig Ae star. We find that AB Aur is probably resolved at 18.7 micron with an angular diameter of 1.2" at a surface brightness of 3.5 Jy/arcsec^2. Most of the dust mass detected at millimeter wavelengths does not contribute to the 18.7 micron emission, which is plausibly explained if the system possesses a relatively cold, massive disk. We find that models...

Source: http://arxiv.org/abs/astro-ph/0303064v1

41
41

Sep 18, 2013
09/13

by
William Y. C. Chen

texts

######
eye 41

######
favorite 0

######
comment 0

Let $P_{n,k}$ be the number of permutations $\pi$ on [n]={1, 2,..., n} such that the length of the longest increasing subsequences of $\pi$ equals k, and let $M_{2n, k}$ be the number of matchings on [2n] with crossing number k. Define $P_n(x)= \sum_k P_{n,k}x^k$ and $M_{2n}(x)=\sum_{k} M_{2n,k}x^k$. We propose some conjectures on the log-concavity and q-log-convexity of the polynomials $P_n(x)$ and $M_{2n}(x)$. We also introduce the notions of $\infty$-q-log-convexity and...

Source: http://arxiv.org/abs/0806.3392v2

0
0.0

Oct 17, 2019
10/19

by
Shepley S. C. Chen

texts

######
eye 0

######
favorite 0

######
comment 0

18
18

Apr 22, 2019
04/19

by
Curtis C. Chen

texts

######
eye 18

######
favorite 0

######
comment 0

(With apologies to Teresa Nielsen Hayden) Today's the day! You can now buy Thursday's Children in paperback or Kindle editions: Attack of the stacks of paperbacks My friend Kenna checks the eBook I know traditionally published authors may wait as long as two years from the time they submit a finished manuscript to when the book actually goes on sale, and I imagine that's rather torturous. It's been maybe five months since DeeAnn and I started working on Thursday's Children, and though I'm very...

19
19

Apr 22, 2019
04/19

by
Curtis C. Chen

http://snout.org/512 Archived from iTunes at https://itunes.apple.com/us/podcast/512-words-or-fewer/id292779523. Items in this collection are restricted.

Topics: podcast, itunes, apple

3
3.0

Oct 17, 2019
10/19

by
Shepley S. C. Chen

texts

######
eye 3

######
favorite 0

######
comment 0

8
8.0

Jan 5, 2018
01/18

by
Knight, David C,Chen, Linda

texts

######
eye 8

######
favorite 2

######
comment 0

Defines the important features of the earth both as an individual planet and as a member of our solar system

25
25

Sep 19, 2013
09/13

by
Dan Abramovich; Jiun C. Chen

texts

######
eye 25

######
favorite 0

######
comment 0

We consider two cases of birational transformations of Q-Gorenstein threefolds: the case of a terminal flop and the case of a Francia flip. In the first case we show that, if one replaces the threefolds by their canonical covering stacks, the the flop coincides with the moduli stack of perverse point sheaves. This adds to a result of Kawamata showing the derived equivalence. Our construction has the drawback that the moduli space is defined using a presentation of the stack. In the second case...

Source: http://arxiv.org/abs/math/0304354v1

61
61

Sep 18, 2014
09/14

by
Jimin Song; Kevin C Chen

texts

######
eye 61

######
favorite 0

######
comment 0

Recently, a wealth of epigenomic data has been generated by biochemical assays and next-generation sequencing (NGS) technologies. In particular, histone modification data generated by the ENCODE project and other large-scale projects show specific patterns associated with regulatory elements in the human genome.It is important to build a unified statistical model to decipher the patterns of multiple histone modifications in a cell type to annotate chromatin states such as transcription start...

Topic: Bioinformatics

Source: http://biorxiv.org/content/early/2014/03/09/002725-0

35
35

Sep 20, 2013
09/13

by
Dan Abramovich; Jiun C. Chen

texts

######
eye 35

######
favorite 0

######
comment 0

Given a birational modification $X \to Y$ of complex projective varieties with fiber dimension 1 and rational singularities, consider the main component of Bridgeland's moduli space $W \to Y$ of perverse point sheaves on $X/Y$. We give criteria for the normalization of $W$ to coincide with the transform (flip/flop) $X^+ \to Y$ of $X \to Y$. First, this holds if the exceptional loci of $X \to Y$ and $W \to Y$ have codimension $>1$. Second, if the ideal sheaf of $X \times_Y X^+$ is flat over...

Source: http://arxiv.org/abs/math/0304353v2

40
40

Sep 18, 2013
09/13

by
Y. C. Chen; A. H. Castro Neto

texts

######
eye 40

######
favorite 0

######
comment 0

We propose an effective two-dimensional quantum non-linear sigma model combined with classical percolation theory to study the magnetic properties of site diluted layered quantum antiferromagnets like La$_{2}$Cu$_{1-x}$M$_x$O$_{4}$ (M$=$Zn, Mg). We calculate the staggered magnetization at zero temperature, $M_s(x)$, the magnetic correlation length, $\xi(x,T)$, the NMR relaxation rate, $1/T_1(x,T)$, and the N\'eel temperature, $T_N(x)$, in the renormalized classical regime. Due to quantum...

Source: http://arxiv.org/abs/cond-mat/9903113v2

44
44

Sep 23, 2013
09/13

by
Kwai-Kong Ng; Y. C. Chen

texts

######
eye 44

######
favorite 0

######
comment 0

We present a comprehensive numerical study on the ground state phase diagram of the two-dimensional hardcore boson extended Hubbard model with nearest ($V_1$) and next nearest neighbor ($V_2$) repulsions. In addition to the quantum solid and superfluid phases, we report the existence of striped supersolid and three-quarter (quarter) filled supersolid at commensurate density $\rho=0.75$ (0.25) due to the interplay of $V_1$ and $V_2$ interactions. The nature of three-quarter filled supersolid and...

Source: http://arxiv.org/abs/0710.3463v1

45
45

Sep 22, 2013
09/13

by
L. C. Chen; F. Y. Wu

texts

######
eye 45

######
favorite 0

######
comment 0

We explicitly evaluate the free energy of the random cluster model at its critical point for 0 < q < 4 using an exact result due to Baxter, Temperley and Ashley. It is found that the resulting expression assumes a form which depends on whether $\pi/2\cos^{-1}[\sqrt(q)/2]$ is a rational number, and if it is a rational number whether the denominator is an odd integer. Our consideration leads to new summation identities and, for q = 2, a closed-form evaluation of the integral [1/(4\pi^2)]...

Source: http://arxiv.org/abs/cond-mat/0501228v2

97
97

Jul 20, 2013
07/13

by
William Y. C. Chen; Lewis H. Liu

texts

######
eye 97

######
favorite 0

######
comment 0

We give a solution to a problem posed by Corteel and Nadeau concerning permutation tableaux of length n and the number of occurrences of the dashed pattern 32--1 in permutations on [n]. We introduce the inversion number of a permutation tableau. For a permutation tableau T and the permutation $\pi$ obtained from T by the bijection of Corteel and Nadeau, we show that the inversion number of T equals the number of occurrences of the dashed pattern 32--1 in the reverse complement of $\pi$. We also...

Source: http://arxiv.org/abs/1007.5019v1

36
36

Sep 20, 2013
09/13

by
William Y. C. Chen; Kathy Q. Ji

texts

######
eye 36

######
favorite 0

######
comment 0

We obtain a finite form of Jacobi's identity and present a combinatorial proof based on the structure of synchronized partitions.

Source: http://arxiv.org/abs/math/0601309v1

39
39

Sep 23, 2013
09/13

by
William Y. C. Chen; Peter L. Guo

texts

######
eye 39

######
favorite 0

######
comment 0

Motivated by the question of finding a type B analogue of the bijection between oscillating tableaux and matchings, we find a correspondence between oscillating m-rim hook tableaux and m-colored matchings, where m is a positive integer. An oscillating m-rim hook tableau is defined as a sequence $(\lambda^0,\lambda^1,...,\lambda^{2n})$ of Young diagrams starting with the empty shape and ending with the empty shape such that $\lambda^{i}$ is obtained from $\lambda^{i-1}$ by adding an m-rim hook...

Source: http://arxiv.org/abs/1105.4306v1

50
50

Sep 23, 2013
09/13

by
William Y. C. Chen; Kathy Q. Ji

texts

######
eye 50

######
favorite 0

######
comment 0

In answer to a question of Andrews about finding combinatorial proofs of two identities in Ramanujan's "Lost" Notebook, we obtain weighted forms of Euler's theorem on partitions with odd parts and distinct parts. This work is inspired by the insight of Andrews on the connection between Ramanujan's identities and Euler's theorem. Our combinatorial formulations of Ramanujan's identities rely on the notion of rooted partitions. Iterated Dyson's map and Sylvester's bijection are the main...

Source: http://arxiv.org/abs/math/0510121v1

37
37

Sep 22, 2013
09/13

by
W. C. Chen; X. D. Li

texts

######
eye 37

######
favorite 0

######
comment 0

In this letter we discuss two possible reasons which cause the observed braking indices n of young radio pulsars to be smaller than 3: (a) the evolving spin-down model of the magnetic field component $B_{\perp}$ increases with time; (b) the extrinsic braking torque model in which the tidal torques exerted on the pulsar by the fallback disk, and carries away the spin angular momentum from the pulsar. Based on some simple assumptions, we derive the expression of the braking indices, and calculate...

Source: http://arxiv.org/abs/astro-ph/0603012v4

26
26

Sep 21, 2013
09/13

by
D. Zhang; G. Rong; J. C. Chen

texts

######
eye 26

######
favorite 0

######
comment 0

A global analysis of the full amplitudes for $e^+e^- \to$ VP (Vector and Pseudoscalar) channels at $\sqrt{s}$ =3.773 GeV and 3.670 GeV, which were measured by the CLEO-c Collaboration, shows that those measurements are essentially nontrivial for searching for the $\psi(3770)$ non-$D\bar D$ decays. Unlike the nearly negative verdict on the $\psi(3770)$ strong decays to the VP channels in the original analysis of the CLEO-c data, there exist some unusual solutions that predict the remarkable...

Source: http://arxiv.org/abs/0808.0091v5

24
24

Sep 17, 2013
09/13

by
G. Rong; D. Zhang; J. C. Chen

texts

######
eye 24

######
favorite 0

######
comment 0

We review the progress on experimental studies of the non-$D\bar D$ decays of the $\psi(3770)$ resonance. With the world average of the observed cross sections for $D\bar D$ production measured at 3.773 GeV by the MARK-I, MARK-II, BES and CLEO Collaborations, combined together with the cross section for $\psi(3770)$ production at its peak as well as initial state radiative correction factor, we find that the non-$D\bar D$ branching fraction of $\psi(3770)$ decays is $B[\psi(3770)\to {\rm...

Source: http://arxiv.org/abs/1003.3523v1

55
55

Sep 22, 2013
09/13

by
William Y. C. Chen; Peter L. Guo

texts

######
eye 55

######
favorite 0

######
comment 0

Let $Q_n$ denote the $n$-dimensional hypercube with the vertex set $V_n=\{0,1}^n$. A 0/1-polytope of $Q_n$ is a convex hull of a subset of $V_n$. This paper is concerned with the enumeration of equivalence classes of full-dimensional 0/1-polytopes under the symmetries of the hypercube. With the aid of a computer program, Aichholzer completed the enumeration of equivalence classes of full-dimensional 0/1-polytopes for $Q_4$, $Q_5$, and those of $Q_6$ up to 12 vertices. In this paper, we present...

Source: http://arxiv.org/abs/1101.0410v1

46
46

Sep 23, 2013
09/13

by
William Y. C. Chen; Lisa H. Sun

texts

######
eye 46

######
favorite 0

######
comment 0

We present a computer algebra approach to proving identities on Bernoulli polynomials and Euler polynomials by using the extended Zeilberger's algorithm given by Chen, Hou and Mu. The key idea is to use the contour integral definitions of the Bernoulli and Euler numbers to establish recurrence relations on the integrands. Such recurrence relations have certain parameter free properties which lead to the required identities without computing the integrals.

Source: http://arxiv.org/abs/0810.0438v3

0
0.0

Jun 28, 2018
06/18

by
H. H. Jen; Y. -C. Chen

texts

######
eye 0

######
favorite 0

######
comment 0

We investigate the spectral properties of the biphoton state from the cascade emissions of cold atomic ensembles, which composes of a telecommunication photon (signal) followed by an infrared one (idler) via four-wave mixing.\ With adiabatic conditions for Gaussian driving pulses of width $\tau$, the spectrum of the biphoton state has the form of a Gaussian that conserves signal and idler photon energies within $\hbar/\tau$ modulated by a Lorentzian with a superradiant linewidth.\ Multiplexing...

Topic: Quantum Physics

Source: http://arxiv.org/abs/1510.01859

36
36

Sep 20, 2013
09/13

by
M. Jura; C. Chen; P. Plavchan

texts

######
eye 36

######
favorite 0

######
comment 0

We have obtained 11.7 micron and 17.9 micron images at the Keck I telescope of the circumstellar dust emission from OH 231.8+4.2, an evolved mass-losing red giant with a well studied bipolar outflow. We detect both a central unresolved point source and extended emission which is aligned with the bipolar outflow seen on larger scales. We find that the unresolved central source can be explained by an opaque, flared disk with an outer radius near 300 AU and an outer temperature of about 130 K. One...

Source: http://arxiv.org/abs/astro-ph/0204027v1

26
26

Sep 18, 2013
09/13

by
William Y. C. Chen; Deheng Xu

texts

######
eye 26

######
favorite 0

######
comment 0

By a re-examination of MacMahon's original proof of his celebrated theorem on the distribution of the major indices over permutations, we give a reformulation of his argument in terms of the structure of labeled partitions. In this framework, we are able to establish a decomposition theorem for labeled partitions that leads to a simple bijective proof of Wachs' formula on the q-derangement numbers.

Source: http://arxiv.org/abs/math/0606481v1

51
51

Sep 19, 2013
09/13

by
William Y. C. Chen; Carol J. Wang

texts

######
eye 51

######
favorite 0

######
comment 0

Noncrossing linked partitions arise in the study of certain transforms in free probability theory. We explore the connection between noncrossing linked partitions and colored Motzkin paths. A (3,2)-Motzkin path can be viewed as a colored Motzkin path in the sense that there are three types of level steps and two types of down steps. A large (3,2)-Motzkin path is defined to be a (3,2)-Motzkin path for which there are only two types of level steps on the x-axis. We establish a one-to-one...

Source: http://arxiv.org/abs/1009.0176v1

62
62

Sep 22, 2013
09/13

by
William Y. C. Chen; Christian M. Reidys

texts

######
eye 62

######
favorite 0

######
comment 0

We study two variations of the Brauer algebra $B_n(x)$. The first is the algebra $A_n(x)$, which generalizes the Brauer algebra by considering loops. The second is the algebra $L_n(x)$, the $A_n(x)$-subalgebra generated by diagrams without horizontal arcs. $A_n(x)$ and $L_n(x)$ have for $x \neq 0$ an hereditary-chain indexed by all integers. Following the ideas of Martin in the context of the partition algebra, and Doran et al. for the Brauer algebra, we study semisimplicity of $A_n(x)$ using...

Source: http://arxiv.org/abs/0906.3428v1

4
4.0

Jun 28, 2018
06/18

by
William Y. C. Chen; Ken Y. Zheng

texts

######
eye 4

######
favorite 0

######
comment 0

Let $p(n)$ denote the partition function. Desalvo and Pak proved the log-concavity of $p(n)$ for $n>25$ and the inequality $\frac{p(n-1)}{p(n)}\left(1+\frac{1}{n}\right)>\frac{p(n)}{p(n+1)}$ for $n>1$. Let $r(n)=\sqrt[n]{p(n)/n}$ and $\Delta$ be the difference operator respect to $n$. Desalvo and Pak pointed out that their approach to proving the log-concavity of $p(n)$ may be employed to prove a conjecture of Sun on the log-convexity of $\{r(n)\}_{n\geq 61}$, as long as one finds an...

Topics: Combinatorics, Mathematics, Number Theory

Source: http://arxiv.org/abs/1511.02558

51
51

Sep 19, 2013
09/13

by
M. Jura; C. Chen; M. W. Werner

texts

######
eye 51

######
favorite 0

######
comment 0

We have used the Keck I telescope to resolve at mid-infrared wavelengths the dust emission from HD 56126 (IRAS 07134+1005), a post-Asymptotic Giant Branch carbon star with a detached dust shell. The gross morphology of the image can be explained by a strong wind which started to die about 1500 years ago. If the star had an effective temperature near 2600 K when it was losing a large amount of mass, then during the past 1500 years, the average value of dT/dt has been +2.2 K/yr. With such a time...

Source: http://arxiv.org/abs/astro-ph/0010038v1

42
42

Sep 22, 2013
09/13

by
William Y. C. Chen; Amy M. Fu

texts

######
eye 42

######
favorite 0

######
comment 0

We show that several classical bilateral summation and transformation formulas have semi-finite forms. We obtain these semi-finite forms from unilateral summation and transformation formulas. Our method can be applied to derive Ramanujan's $_1\psi_1$ summation, Bailey's $_2\psi_2$ transformations, and Bailey's $_6\psi_6$ summation.

Source: http://arxiv.org/abs/math/0501242v1

37
37

Jul 20, 2013
07/13

by
D. Zhang; R. Gang; J. C. Chen

texts

######
eye 37

######
favorite 0

######
comment 0

A generator with $\alpha^2$ order radiative correction effects, including both the initial state radiative corrections and the photon vacuum polarization corrections, is built for the full simulation of $e^+e^- \to hadrons $ in cross section scan experiment in the quarkonium energy region. The contributions from the hadron production structures including the resonances of $1^{--}$ quarkonium families and the light hadrons spectrum below 2 GeV as well as the QED continuum hadron spectrum are all...

Source: http://arxiv.org/abs/hep-ph/0604264v2

1
1.0

Oct 17, 2019
10/19

by
Shepley S. C. Chen; Won-Mok Park

texts

######
eye 1

######
favorite 0

######
comment 0

67
67

Sep 18, 2013
09/13

by
Y. C. Chen; T. K. Lee

texts

######
eye 67

######
favorite 0

######
comment 0

We propose a correlated spin-singlet-pairs wave function to describe the spin-gap phase of the one-dimensional $t-J$ model at low density. Adding a Jastrow factor with a variational parameter, $\nu$, first introduced by Hellberg and Mele, is shown to correctly describe the long-range behavior expected for the Luther-Emery phase. Using the variational Monte Carlo method we establish a relation between $\nu$ and the Luttinger exponent $K_\rho$, $K_\rho=\frac{1}{2\nu}$.

Source: http://arxiv.org/abs/cond-mat/9604191v1

42
42

Sep 21, 2013
09/13

by
Y. C. Chen; T. K. Lee

texts

######
eye 42

######
favorite 0

######
comment 0

The initial trial wave function used in a simple ground-state projection method, the power method, is systematically improved by using Lanczos algorithm. Much faster convergence to the ground state achieved by using these wave functions significantly reduces the effect of the fermion sign problem. The energy, spin and charge correlation functions are calculated for the ground states of the two-dimensional $t-J$ model. Results for an $8\times8$ cluster with 42 and 26 electrons are presented. The...

Source: http://arxiv.org/abs/cond-mat/9404095v1

24
24

Sep 23, 2013
09/13

by
L. C. Chen; F. Y. Wu

texts

######
eye 24

######
favorite 0

######
comment 0

We consider a directed percolation process on an ${\cal M}$ x ${\cal N}$ rectangular lattice whose vertical edges are directed upward with an occupation probability y and horizontal edges directed toward the right with occupation probabilities x and 1 in alternate rows. We deduce a closed-form expression for the percolation probability P(x,y), the probability that one or more directed paths connect the lower-left and upper-right corner sites of the lattice. It is shown that P(x,y) is critical...

Source: http://arxiv.org/abs/cond-mat/0511296v2

1
1.0

Jun 30, 2018
06/18

by
William Y. C. Chen; Amy M. Fu

texts

######
eye 1

######
favorite 0

######
comment 0

In this paper, we introduce the notion of a grammatical labeling to describe a recursive process of generating combinatorial objects based on a context-free grammar. For example, by labeling the ascents and descents of a Stirling permutation, we obtain a grammar for the second-order Eulerian polynomials. By using the grammar for $0$-$1$-$2$ increasing trees given by Dumont, we obtain a grammatical derivation of the generating function of the Andr\'e polynomials obtained by Foata and...

Topics: Mathematics, Combinatorics

Source: http://arxiv.org/abs/1408.1859

1
1.0

Oct 17, 2019
10/19

by
Shepley S. C. Chen; Won-Mok Park

texts

######
eye 1

######
favorite 0

######
comment 0

40
40

Jul 19, 2013
07/13

by
Y. C. Chen; T. K. Lee

texts

######
eye 40

######
favorite 0

######
comment 0

The spin, charge and pairing correlation functions for the ground state of two-dimensional $t-J$ model are calculated by using the power method which projects out the ground state from a variational wave function. ``Exact'' results are obtained for $10\times10$ and $8\times8$ lattices with low particle densities. The results are surprisingly similar to that of one-dimensional $t-J$ model. The phenomenology is almost perfectly correlated with the concept of Tomonaga-Luttinger liquid and it is...

Source: http://arxiv.org/abs/cond-mat/9401039v1

39
39

Sep 18, 2013
09/13

by
William Y. C. Chen; David G. L. Wang

texts

######
eye 39

######
favorite 0

######
comment 0

We show that the distribution of the coefficients of the q-derangement numbers is asymptotically normal. We also show that this property holds for the q-derangement numbers of type B.

Source: http://arxiv.org/abs/0806.2092v1

44
44

Sep 18, 2013
09/13

by
William Y. C. Chen; Cindy C. Y. Gu

texts

######
eye 44

######
favorite 0

######
comment 0

We prove the reverse ultra log-concavity of the Boros-Moll polynomials. We further establish an inequality which implies the log-concavity of the sequence $\{i!d_i(m)\}$ for any $m\geq 2$, where $d_i(m)$ are the coefficients of the Boros-Moll polynomials $P_m(a)$. This inequality also leads to the fact that in the asymptotic sense, the Boros-Moll sequences are just on the borderline between ultra log-concavity and reverse ultra log-concavity. We propose two conjectures on the log-concavity and...

Source: http://arxiv.org/abs/0809.0127v2

34
34

Sep 18, 2013
09/13

by
William Y. C. Chen; Toufik Mansour; Sherry H. F. Yan

texts

######
eye 34

######
favorite 0

######
comment 0

We show that matchings avoiding certain partial patterns are counted by the 3-Catalan numbers. We give a characterization of 12312-avoiding matchings in terms of restrictions on the corresponding oscillating tableaux. We also find a bijection between Schr\"oder paths without peaks at level one and matchings avoiding both patterns 12312 and 121323. Such objects are counted by the super-Catalan numbers or the little Schr\"{o}der numbers. A refinement of the super-Catalan numbers is...

Source: http://arxiv.org/abs/math/0504342v1

37
37

Sep 21, 2013
09/13

by
L C Chen; X L Nguyen; Y S Shu

texts

######
eye 37

######
favorite 0

######
comment 0

This article presents a new optical measurement method employing a HSI (Hue, Saturation and Intensity) colour model to form trapezoidal structured patterns for morphology reconstruction of a measured object at a high speed. Profilometry on objects having non-monochromatic surfaces is considered as one of the remaining most challenges faced by the currently existing structured-light projection methods since the surface reflectivity to red, green and blue light may vary significantly. To address...

Source: http://arxiv.org/abs/1008.1302v1

29
29

Sep 18, 2013
09/13

by
William Y. C. Chen; Ernest X. W. Xia

texts

######
eye 29

######
favorite 0

######
comment 0

In their study of a quartic integral, Boros and Moll discovered a special class of Jacobi polynomials, which we call the Boros-Moll polynomials. Kauers and Paule proved the conjecture of Moll that these polynomials are log-concave. In this paper, we show that the Boros-Moll polynomials possess the ratio monotone property which implies the log-concavity and the spiral property. We conclude with a conjecture which is stronger than Moll's conjecture on the $\infty$-log-concavity.

Source: http://arxiv.org/abs/0806.4333v2

55
55

Sep 22, 2013
09/13

by
William Y. C. Chen; Qing-Hu Hou; Yan-Ping Mu

texts

######
eye 55

######
favorite 0

######
comment 0

For a hypergeometric series $\sum_k f(k,a, b, ...,c)$ with parameters $a, b, >...,c$, Paule has found a variation of Zeilberger's algorithm to establish recurrence relations involving shifts on the parameters. We consider a more general problem concerning several similar hypergeometric terms $f_1(k, a, b,..., c)$, $f_2(k, a,b, ..., c)$, $...$, $f_m(k, a, b, ..., c)$. We present an algorithm to derive a linear relation among the sums $\sum_k f_i(k,a,b,...,c)$ $(1\leq i \leq m)$. Furthermore,...

Source: http://arxiv.org/abs/0908.1328v1

37
37

Sep 18, 2013
09/13

by
H. M. O'Keeffe; E. O'Sullivan; M. C. Chen

texts

######
eye 37

######
favorite 0

######
comment 0

The SNO+ liquid scintillator experiment is under construction in the SNOLAB facility in Canada. The success of this experiment relies upon accurate characterization of the liquid scintillator, linear alkylbenzene (LAB). In this paper, scintillation decay times for alpha and electron excitations in LAB with 2 g/L PPO are presented for both oxygenated and deoxygenated solutions. While deoxygenation is expected to improve pulse shape discrimination in liquid scintillators, it is not commonly...

Source: http://arxiv.org/abs/1102.0797v1

1
1.0

Jun 28, 2018
06/18

by
William Y. C. Chen; Qing-Hu Hou; Doron Zeilberger

texts

######
eye 1

######
favorite 0

######
comment 0

Many combinatorial sequences (for example, the Catalan and Motzkin numbers) may be expressed as the constant term of $P(x)^k Q(x)$, for some Laurent polynomials $P(x)$ and $Q(x)$ in the variable $x$ with integer coefficients. Denoting such a sequence by $a_k$, we obtain a general formula that determines the congruence class, modulo $p$, of the indefinite sum $\sum_{k=0}^{rp -1} a_k$, for {\it any} prime $p$, and any positive integer $r$, as a linear combination of sequences that satisfy linear...

Topics: Combinatorics, Mathematics

Source: http://arxiv.org/abs/1509.09070

33
33

Sep 21, 2013
09/13

by
C. T. Shih; Y. C. Chen; T. K. Lee

texts

######
eye 33

######
favorite 0

######
comment 0

The boundary of phase separation of the two-dimensional t-J model is investigated by the power-Lanczos method and Maxwell construction. The method is similar to a variational approach and it determines the lower bound of the phase separation boundary with $J_c/t=0.6\pm 0.1$ in the limit $n_e\sim 1$. In the physical interesting regime of high T_c superconductors where $0.3

Source: http://arxiv.org/abs/cond-mat/9705156v1

32
32

Sep 22, 2013
09/13

by
M. E. Brown; A. L. Smith; C. Chen; M. Adamkovics

texts

######
eye 32

######
favorite 0

######
comment 0

While Saturn's moon Titan appears to support an active methane hydrological cycle, no direct evidence for surface-atmosphere exchange has yet appeared. It is possible that the identified lake-features could be filled with ethane, an involatile long term residue of atmospheric photolysis; the apparent stream and channel features could be ancient from a previous climate; and the tropospheric methane clouds, while frequent, could cause no rain to reach the surface. We report here the detection of...

Source: http://arxiv.org/abs/0908.4087v1

40
40

Sep 21, 2013
09/13

by
J. C. Peng; D. M. Jansen; Y. C. Chen

texts

######
eye 40

######
favorite 0

######
comment 0

The sensitivity of proton-induced $J/\psi$ and $\Upsilon$ production to the possible $\bar u/\bar d$ asymmetry in the nucleon is studied. The ratio of the quarkonium production cross sections at large $x_F$ on hydrogen over deuterium targets, $\sigma (p+p) / \sigma (p+d)$, is shown to be sensitive to this asymmetry. Predictions of various theoretical models for this ratio are presented.

Source: http://arxiv.org/abs/hep-ph/9508244v2

29
29

Sep 18, 2013
09/13

by
William Y. C. Chen; Jiuqiang Liu; Larry X. W. Wang

texts

######
eye 29

######
favorite 0

######
comment 0

A family of $k$-subsets $A_1, A_2, ..., A_d$ on $[n]=\{1,2,..., n\}$ is called a $(d, c)$-cluster if the union $A_1\cup A_2 \cup ... \cup A_d$ contains at most $ck$ elements with $c

Source: http://arxiv.org/abs/math/0605171v3