Imaginary Paths Research Articles

Quantum field theory with ghost pairs

We explicitly show that general local higher-derivative theories with only complex conjugate ghosts and normal real particles are unitary at any perturbative order in the loop expansion. The proof presented here relies on integrating the loop energies on complex paths resulting from the deformation of the purely imaginary paths, when the external energies are continued from imaginary to real values. Contrary to the case of nonlocal theories, where the same integration path was first proposed, for the classes of theories studied here the same procedure is not analytic, but the resulting theory is unitary and unique when the complex ghosts are present in pairs. As an explicit application, a special class of higher-derivative super-renormalizable or finite gravitational and gauge theories turns out to be unitary at any perturbative order if we exclude the complex ghosts from the spectrum of the theory, as it is normally accepted for Becchi-Rouet-Stora-Tyutin (BRST) ghosts. Finally, we propose an analogy between confined gluons in quantum Yang-Mills theory and classical complex pairs in local higher-derivative theories. According to such interpretation, complex ghosts will not appear on shell as asymptotic states because confined in what is natural to name “ghostballs.”

Метод обобщенного импеданса для расчета отражения и прохождения волны через многослойную структуру. Часть 2. Падение волны на прямоугольный барьер

On the basis of generalized impedance method the propagation of single-dimension wave in multi-layer structure which contains the rectangular-type barrier is investigated. The concept of single barrier as a slide which parameters are different from the parameters of all other slides of structure is introduced. It is investigated the variation of position of real negative single barrier along the length of structure. It is found that the entrance impedance along the length of structure is varied by periodic manner. It is found the analytical formulas which simulate the dependencies of real and imaginary parts of entrance media impedances from coordinate along the structure. It is found three basis regimes which correspond to different character of oscillations: regime №1 – precise periodicity, regime №2 – break periodicity, regime №3 – monotonous increasing. It is investigated the coefficient of reflection for all mentioned above cases. It is found that the reflection coefficient from barrier displacement is not depended. It is found the periodic character of changing of amplitude and phase of reflected wave and also reflection coefficient when the height of barrier is varied. For interpretation of observed dependencies it is proposed the model of resonance inside of barrier. It is investigated the special feature of wave propagation when the barrier has complex character. It is investigated the case when the real path of wave number of barrier medium is established constant but imaginary path of the same number is varied in wide boundaries. It is established that reflection coefficient started by zero when the imaginary part of wave number is equal to zero. When imaginary part of wave number increases the reflection coefficient smooth increases in limit goes to unit. The passing coefficient also smooth decreases but more quickly then reflection coefficient and in limit goes to zero. The absorb coefficient started by zero at first smooth increases and after reaching of maximum smooth decreases in limit goes to zero. It is investigated the case when real and imaginary paths of barrier medium wave number simultaneous increase in equally proportion. It is found that in this case on the smooth curves for coefficients ob reflection, passing and absorb it is putted the oscillations. The character of oscillations is explained in the frames of resonance model.

The Potential of a Thick Present through Undefined Causality and Non-Locality.

This paper elaborates on the interpretation of time and entanglement, offering insights into the possible ontological nature of information in the emergence of spacetime, towards a quantum description of gravity. We first investigate different perspectives on time and identify in the idea of a “thick present” the only element of reality needed to describe evolution, differences, and relations. The thick present is connected to a spacetime information “sampling rate”, and it is intended as a time symmetric potential bounded between a causal past of irreversible events and a still open future. From this potential, spacetime emerges in each instant as a space-like foliation (in a description based on imaginary paths). In the second part, we analyze undefined causal orders to understand how their potential could persist along the thick present instants. Thanks to a C-NOT logic and the concept of an imaginary time, we derive a description of entanglement as the potential of a logically consistent open choice among imaginary paths. We then conceptually map the imaginary paths identified in the entanglement of the undefined orders to Closed Time-like Curves (CTC) in the thick present. Considering a universe described through information, CTC are interpreted as “memory loops”, elementary structures encoding the information potential related to the entanglement in both time and space, manifested as undefined causality and non-locality in the emerging foliation. We conclude by suggesting a possible extension of the introduced concepts in a holographic perspective.

A memória na Literatura da Segunda Guerra Mundial: narrações como testemunho histórico e invenção

Este artigo reflete sobre a influência da memória na Literatura da Segunda Guerra Mundial. Focando principalmente na lembrança traumática de soldados alemães que se tornaram posteriormente escritores, o artigo coteja as possibilidades da narração, que compreendem ao mesmo tempo uma parte de relato histórico, ficção e de reorganização, ora intencional, ora não, de suas recordações mais marcantes. O relembrar destes atores, que não pretendem alcançar uma verdade histórica, percorre caminhos imaginados para liberta-se catarticamente do passado traumático. Busca-se aqui também apresentar exemplos de casos em que o testemunho, como realidade pessoal (e não histórica) inconsciente perpassa a narração de forma a construir uma realidade fiel ao autor e a muitos de seus leitores.

Simulation of nanowire tunneling transistors: From the Wentzel–Kramers–Brillouin approximation to full-band phonon-assisted tunneling

Nanowire band-to-band tunneling field-effect transistors (TFETs) are simulated using the Wentzel–Kramers–Brillouin (WKB) approximation and an atomistic, full-band quantum transport solver including direct and phonon-assisted tunneling (PAT). It is found that the WKB approximation properly works if one single imaginary path connecting the valence band (VB) and the conduction band (CB) dominates the tunneling process as in direct band gap semiconductors. However, PAT is essential in Si and Ge nanowire TFETs where multiple, tightly-coupled, imaginary paths exist between the VB and the CB.

Has inflation targeting improved social welfare in practice?

This article verifies empirically the proposition that inflation targeting can improve social welfare. To analyse this, we construct a cashless small open-economy model conforming to the New Keynesian Open-Economy Macroeconomics and use data in the United Kingdom. We estimate the feedback rule, before estimating the deep parameters using GMM. Using the estimated structural model and identified shock processes, we simulate the imaginary paths of the nominal interest rate, producer price index inflation rate and output if the central bank has not adopted an inflation targeting policy. This simulation shows that the variances of output and the inflation rate under a noninflation targeting regime are larger than those under the actual inflation targeting regime. We also calculate social loss, as defined by the second-order approximated utility function under each regime. The results indicate that social loss brought about by an inflation targeting regime is less than that associated with a noninflation targeting regime.

Mismatch cancellation in quadrature bandpass ΔΣ modulators using an error shaping technique

A technique for shaping component mismatch error in the real and imaginary paths of a complex (quadrature) /spl Delta//spl Sigma/ are studied and simulated. Complex bandpass /spl Delta//spl Sigma/ modulators provide improved performance over a pair of real bandpass /spl Delta//spl Sigma/ modulators of the same order in the conversion of narrow-band quadrature intermediate frequency (IF) signals. This is possible due to elimination of redundant conjugate pairs of poles and zeros in its noise and signal transfer function. Mismatches in the modulators real and imaginary paths, however, results in spectral leakage of image band interference and image band quantization noise to the passband of the converted output. Strategic pole-zero placement, as well as adaptive techniques has been studied in earlier works. The work presented here takes advantage of the inherent dual paths of the complex bandpass /spl Delta//spl Sigma/ modulator to reduce component mismatch effects using a switched capacitor error shaping technique.

The Sky River

imaginary paths visible only to inner eyes of men learned scientific matters. They corresponded to imaginary lines which we have set sky, such as equinoctial colure and azimuth circle. For them, as for us, most important ones were Red Road (our celestial equator) and Yellow Road (our ecliptic). But although expression road of occurs very rarely early Chinese literature, it is an anomaly and an exception. For almost everyone pale streak sky was a river. sky river had no single name China. Chinese were more fortunate than we who are restricted to single phrase Milky Way. They named it after two of their major rivers, north (our Yellow River) and famous tributary of Yangtze I(iang south of it. These names, combined with a set of adjectival stereotypes-heavenly, cloudy, starry, silver, and occasionally luminousyielded a considerable variety of combinations, such as Ho or Ho, Cloudy Ho, Starry Han, Silver and like. use of first of these epithets might be styled locative group, second nebular group, third group, and fourth esthetic group of names. oldest literary references to sky river occur two passages Shih ching. In both of them it is called Han; once it is cloudy13 and once in sky.'4 Possibly this priority was given to Han River because earthly Han was markedly more clear and sparkling than normally sluggish and muddy Ho. (Indeed, so rarely was water of clear that medieval times such a remarkable phenomenon was of13 Shih, ya, Tang. 14 Shih, Hsiao ya, Ta tung. ficially declared to be a Great Auspicious Token, indicative of special favor of Heaven, on a par with apparition of a phoenix or dragon.)15 By Han times, at least, sky river was regarded as a mysterious emanation from rivers of China, congealed on celestial dome. Fragments of a book that survive from that period contain such statements as virtue of a river spreads its quintessence, it creates a mass of stars above.'6 Hence, the quintessence of becomes Sky Han above.17 Some sources attempt more explicit explanations of presence of this strange stellar stars are formed, they say, out of a primordial breath, which is mystically related to water of earthly rivers. One such source-a very respectable one-states: Now Han is also a dispersed pneuma of Metal, and its source is called Han of When its stars are abundant, water is abundant, and when they are few, we have drought.18 Metal here is purely metaphysical. It is Element whose color is white-revealed also snow, tigers, and death. A couple of centuries later poet-astronomer Chang Heng wrote, The quintessence of water makes Heavenly Han,19 while a minor philosopher of third century, A.D. wrote, The stars are of essence of primordial pneuma-and quintessence of water. This subtle, nebulous vapor drifts upward from terrestrial rivers to form river sky, and the host of stars emerge from it.20 To summarize, glittering stream above is composed of a subtle substance allied to earthly water but transcending it. It is related to all watery and crystalline substances, including rain, frost and snow (I have also read of a great Snow Drift of Skies Zufii legend).21 imagery applied to it literature is exactly same as that applied to distinct stars and also to sparkling and twinkly surfaces of waters on earth. metaphysical correspondence of waters of 15 T'ang liu tien, 4, 18b. 16 t'u kua ti hsiang (Han hsiieh t'ang ts'ung shu ed.), p. lb. 17 Ibid. 18 Shih chi (K'ai ming ed.), 27, Olllb. 19 Chang Heng, Ling hsien (quoted T'ai p'ing yii lan, 8, lOb). 20 Yang Ch'ian, Wu li lun (quoted T'ai p'ing yii lan, 8, lla). 21 Hastings, Encyclopaedia, Vol. VI, 886. 403 This content downloaded from 157.55.39.104 on Sun, 19 Jun 2016 06:47:54 UTC All use subject to http://about.jstor.org/terms Journal of American Oriental Society 94.4 (1974) earth and of heaven is exact, although upper streams are more pure and perfect. As to epithet silver applied occasionally to sky river, a medieval commentator22 on a poem by Tu Fu entitled The Sky Ho writes: autumn comes sky becomes 'silver Ho'. reference is to language of first of two quatrains that make up Tu Fu's poem, which goes something like this: In usual season it allows itself either light or dark: When autumn comes it is dependably distinct and

Interpretation of Fermat's Principle

IN order to demonstrate the possibility that an optical path between two fixed points may be merely stationary, that is, neither maximum nor minimum, Mr. T. Smith1 includes in the infinite number of paths with which an actual path is to be compared those which in one homogeneous medium are non-rectilinear. Thus in Fig. 1, if A is the image of A due to the lens PQ, the actual path APAB is compared with the longer and shorter imaginary paths APCB and AQDB.