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61.
Ricardo?Couso-Santamaría José?D.?Edelstein Ricardo?SchiappaEmail author Marcel?Vonk 《Communications in Mathematical Physics》2015,335(1):285-307
The holomorphic anomaly equations describe B-model closed topological strings in Calabi–Yau geometries. Having been used to construct perturbative expansions, it was recently shown that they can also be extended past perturbation theory by making use of resurgent transseries. These yield formal nonperturbative solutions, showing integrability of the holomorphic anomaly equations at the nonperturbative level. This paper takes such constructions one step further by working out in great detail the specific example of topological strings in the mirror of the local \({\mathbb{C}\mathbb{P}^2}\) toric Calabi–Yau background, and by addressing the associated (resurgent) large-order analysis of both perturbative and multi-instanton sectors. In particular, analyzing the asymptotic growth of the perturbative free energies, one finds contributions from three different instanton actions related by \({\mathbb{Z}_3}\) symmetry, alongside another action related to the Kähler parameter. Resurgent transseries methods then compute, from the extended holomorphic anomaly equations, higher instanton sectors and it is shown that these precisely control the asymptotic behavior of the perturbative free energies, as dictated by resurgence. The asymptotic large-order growth of the one-instanton sector unveils the presence of resonance, i.e., each instanton action is necessarily joined by its symmetric contribution. The structure of different resurgence relations is extensively checked at the numerical level, both in the holomorphic limit and in the general nonholomorphic case, always showing excellent agreement with transseries data computed out of the nonperturbative holomorphic anomaly equations. The resurgence relations further imply that the string free energy displays an intricate multi-branched Borel structure, and that resonance must be properly taken into account in order to describe the full transseries solution. 相似文献
62.
Yoo JW Edelstein RS Lincoln DM Raju NP Xia C Pokhodnya KI Miller JS Epstein AJ 《Physical review letters》2006,97(24):247205
Concomitant photoinduced magnetic and electrical phenomena are reported for the organic-based magnetic semiconductor V(TCNE)x (x approximately 2; TCNE=tetracyanoethylene; magnetic ordering temperature Tc approximately 400 K). Upon optical excitation (457.9 nm), the system can be trapped in a thermally reversible photoexcited state, which exhibits reduced magnetic susceptibility and increased conductivity with a simultaneous change in IR absorption spectrum. The multiple photonic effects in V(TCNE)x are proposed to originate from structural changes induced by internal excitation in (TCNE)- anions, which lead to relaxation to a long-lived metastable state. 相似文献
63.
Gold nanoparticles (AuNPs) have been synthesized by greener method using chloroauric acid as precursor and extract of Acorus calamus rhizome as reducing agent. Formation of AuNP was confirmed by the presence of Surface Plasmon Resonance (SPR) peak in UV–Visible spectral analysis. XRD and FT-IR spectral analyses were performed for characterization. SEM images show spherical morphology and HR-TEM images reveal nanosize of AuNPs. The AuNPs were then coated on cotton fabric by pad-dry-cure method and characterized by SEM with EDAX technique. The results reveal the deposition of AuNPs on the surface of cotton fabric. Uncoated cotton, neat extract coated cotton and extract containing AuNPs coated cotton fabrics were then tested for antibacterial activity against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) bacterial strains by AATCC 100 test method. It showed that the extract containing AuNPs coated cotton fabric had higher antibacterial activity than other test samples against E. coli. UV-DRS analysis performed on extract containing AuNPs coated cotton fabric showed improved UV-blocking property than uncoated cotton fabric and neat extract coated cotton fabric. 相似文献
64.
X-ray absorption spectroscopy (XAS) and magnetic circular dichroism (MCD) at the V L{2,3} and C and N K edges reveal bonding and backbonding interactions in films of the 400 K magnetic semiconductor V[TCNE]x approximately 2. In V spectra, d{xy}-like orbitals are modeled assuming V2+ in an octahedral ligand field, while d{z{2}} and d{x{2}-y{2}} orbitals involved in strong covalent sigma bonding cannot be modeled by atomic calculations. C and N MCD, and differences in XAS from neutral TCNE molecules, reveal spin-polarized molecular orbitals in V[TCNE]x approximately 2 associated with weaker pi bonding interactions that yield its novel properties. 相似文献
65.
Alan S. Edelstein Sendip K. Sengupta Richard L. Carlin O.D. McMasters 《Solid State Communications》1980,34(10):781-783
The transverse and longitudinal acoustic velocities have been measured in the [100] and [111] directions of CeSn3 as a function of temperature for 4.2 ≤ T ≤ 290 K. The elastic constants c44 and increase smoothly with decreasing temperature and become temperature independent below 10 K but the bulk modulus has a 2% decrease at 135 K which is indicative of an electronically driven mode softening. 相似文献
66.
A.S. Edelstein G.E. Brodale R.A. Fisher Carey M. Lisse Norman E. Philips 《Solid State Communications》1985,56(3):271-275
Crystal fields are included in a model calculation of the magnetization of the Kondo compound CeAl3. Using parameters taken from experiment, the predicted magnetization at T=1.4 and 4.2K for applied magnetic fields H less than 10T is in good agreement with experiment. Using this magnetization, the model also correctly predicts the decrease in the specific heat C as a function of H for 0.35 ?T?0.9K. In particular, it correctly predicts that this decrease is approximately linear in H and that is approximately temperature independent. 相似文献
67.
Kushnirenko A Alkhazov G Atamantchouk AG Balatz MY Bondar NF Cooper PS Dauwe LJ Davidenko GV Dersch U Dolgolenko AG Dzyubenko GB Edelstein R Emediato L Endler AM Engelfried J Eschrich I Escobar CO Evdokimov AV Filimonov IS Garcia FG Gaspero M Giller I Golovtsov VL Gouffon P Gülmez E Kangling H Iori M Jun SY Kaya M Kilmer J Kim VT Kochenda LM Konorov I Kozhevnikov AP Krivshich AG Krüger H Kubantsev MA Kubarovsky VP Kulyavtsev AI Kuropatkin NP Kurshetsov VF Kwan S Lach J Lamberto A Landsberg LG 《Physical review letters》2001,86(23):5243-5246
We report new precision measurements of the lifetimes of the Lambda(+)(c) and D0 from SELEX, the charm hadroproduction experiment at Fermilab. Based upon 1630 Lambda(+)(c) and 10 210 D0 decays we observe lifetimes of tau[Lambda(+)(c)] = 198.1+/-7.0+/-5.6 fs and tau[D0] = 407.9+/-6.0+/-4.3 fs. 相似文献
68.
69.
RM. Sekkappan 《Annals of the Institute of Statistical Mathematics》1982,34(1):605-609
Summary Smith (1976,J. R. Statist. Soc., A,139, 183–204) has argued that survey statisticians should attempt to model finite population structures in the same way that
statisticians in other disciplines have to provide models of finite or infinite populations. Following this argument, we suggest
in this paper that an obvious model for a stratified population when auxiliary information regarding variate values is available,
is the one way analysis of covariance model with unequal variances and we consider the problem of estimating the finite population
mean. Finally a possible extension of this result is discussed. 相似文献
70.
Single crystals of Nd3+:RbY2Cl7 were grown by the Bridgman-Stockbarger method. The host crystal contains two slightly inequivalent Y3+ ions, each with an approximate C2v site symmetry. Anti-Stokes emission from the 4G7/2 and 4D3/2 levels was observed after laser excitation of the 4F3/2 and 4F9/2 multiplets. Laser excitation at 413 cm−1 or 453 cm−1 above the 4F3/2 multiplet resulted in emission from the 2P1/2 level. Laser site-selective upconverted emission spectra have been measured, as well as their emission transients and power dependence. Possible excited state absorption and energy-transfer upconversion (ETU) mechanisms are proposed and discussed. Due to the smaller crystal field and a somewhat different energy level structure for the Nd3+ ions in RbY2Cl7 as compared with those observed for Nd3+ in fluoride or oxide hosts, the 4G7/2 and 4D3/2 multiplets are populated under 4F3/2 excitation in a three and four step ETU process, respectively, instead of in a two and three step process as observed for the lighter hosts. 相似文献