Microlocal spectrum condition and Hadamard form for vector-valued quantum fields in curved spacetime

Some years ago, Radzikowski has found a characterization of Hadamard states for scalar quantum fields on a four-dimensional globally hyperbolic spacetime in terms of a specific form of the wavefront set of their two-point functions (termed `wavefront set spectrum condition'), thereby initiating a major progress in the understanding of Hadamard states and the further development of quantum field theory in curved spacetime. In the present work, we extend this important result on the equivalence of the wavefront set spectrum condition with the Hadamard condition from scalar fields to vector fields (sections in a vector bundle) which are subject to a wave-equation and are quantized so as to fulfill the covariant canonical commutation relations, or which obey a Dirac equation and are quantized according to the covariant anti-commutation relations, in any globally hyperbolic spacetime having dimension three or higher. In proving this result, a gap which is present in the published proof for the scalar field case will be removed. Moreover we determine the short-distance scaling limits of Hadamard states for vector-bundle valued fields, finding them to coincide with the corresponding flat-space, massless vacuum states.Comment: latex2e, 41 page

Continuity of symplectically adjoint maps and the algebraic structure of Hadamard vacuum representations for quantum fields on curved spacetime

We derive for a pair of operators on a symplectic space which are adjoints of each other with respect to the symplectic form (that is, they are sympletically adjoint) that, if they are bounded for some scalar product on the symplectic space dominating the symplectic form, then they are bounded with respect to a one-parametric family of scalar products canonically associated with the initially given one, among them being its ``purification''. As a typical example we consider a scalar field on a globally hyperbolic spacetime governed by the Klein-Gordon equation; the classical system is described by a symplectic space and the temporal evolution by symplectomorphisms (which are symplectically adjoint to their inverses). A natural scalar product is that inducing the classical energy norm, and an application of the above result yields that its ``purification'' induces on the one-particle space of the quantized system a topology which coincides with that given by the two-point functions of quasifree Hadamard states. These findings will be shown to lead to new results concerning the structure of the local (von Neumann) observable-algebras in representations of quasifree Hadamard states of the Klein-Gordon field in an arbitrary globally hyperbolic spacetime, such as local definiteness, local primarity and Haag-duality (and also split- and type III_1-properties). A brief review of this circle of notions, as well as of properties of Hadamard states, forms part of the article.Comment: 42 pages, LaTeX. The Def. 3.3 was incomplete and this has been corrected. Several misprints have been removed. All results and proofs remain unchange

Gall-inducing Aphids (Hemiptera: Aphidoidea: Eriosomatinae) Associated with Salicaceae and Ulmaceae in Razavi Khorasan Province, with New Records for Fauna of Iran

A survey of gall-inducing aphids on elm and poplar trees was carried out during 2017 in Razavi Khorasan province, NE Iran. As a result, 15 species of gall-inducing aphids from 5 genera, all belonging to the subfamily Eriosomatinae, were recorded on 6 host plant species. The collected species included the genera Eriosoma, Kaltenbachiella, Pemphigus, Tetraneura and Thecabius. Pemphigus passeki Börner (Hemiptera: Aphididae) and Pemphigus populinigrae (Schrank) (Hemiptera: Aphididae) on Populus nigra var. italica (Salicaceae) were new records for the Iranian aphid fauna. Both new recorded species belong to the tribe Pem-phigini, subfamily Eriosomatinae. Among the identified species, 8 aphid species were new records for Razavi Khorasan province

A Generalized Modular Multilevel Current Source Inverter

This paper proposes a novel topology of multilevel current source inverter which is suitable to apply in low/medium voltage. The proposed topology is capable of producing desirable bidirectional output current levels. Furthermore, it can employ symmetrical DC current sources as well as asymmetrical ones which is a significant advantage. Asymmetrical mode makes it possible to generate a great number of output levels by appropriate selection of DC current source magnitude, needless to make changes in the hardware of the inverter. As a result, various methods are presented to compute the magnitude of needed DC current sources. In comparison to the conventional H-Bridge inverter (CHB), the proposed inverter has lessened the number of required DC current sources, switches as well as related gate driver circuits. The reduced number of required components has leads to cost and volume advantages. In addition, the control layout has become simpler. Reduction of power loss as a result of reduced number of on-state switches is the other merit of the proposed inverter. To evaluate the efficiency of the proposed inverter, its simulation and experimental results are extracted including results of various methods of determining DC current source magnitude

Keanekaragaman Kumbang Curculionid pada Berbagai Tipe Penggunaan Lahan di Kawasan Hutan Harapan, Jambi

Family Curculionidae is a group of beetles (Order Coleoptera) that have an important role in different ecosystems, either as herbivores or pollinators. Land-use change, mainly from natural forest to agriculture area can have negative affect on population of curculionid beetles. The objective of this research was to study seasonal diversity, both in terms of species richness and abundance of curculionid beetles in different land-use types in Hutan Harapan landscape, Jambi. Curculionids were sampled using fogging methods. The study was conducted in four different land-use types i.e. forest, jungle rubber, rubber, and oil palm plantations in both dry (from May to September 2013) and rainy season (from November 2013 to February 2014). Four plot each of 50 m x 50 m were set up in the four land use types. We found 1762 individuals belonging to 12 subfamili and 118 species curculionid beetle. The most abundant species was found in forest (81 species) and the lowest was in the rubber plantations (20 species). The most common curculionid that were found in each land-use type were Curculioninae sp.21 (forest), Entiminae sp.06 (jungle rubber), Scolytinae sp.09 (rubber plantation) and Elaeidobius kamerunicus Faust (oil palm plantations). The highest abundance of curculionid was in oil palm plantations (853 individual) and the lowest was in rubber plantations (33 individual). Land-use type and vegetation diversity affect species richness but not abundant of curculionids. Analysis showed that different season significantly affect composition of curculionid in the forest but it has no effect in other land use types

Fermions on adS

We construct the Feynman propagator for Dirac fermions on anti-de Sitter space-time and present an analytic expression for the bi-spinor of parallel transport. We then renormalise the vacuum expectation value of the stress-energy tensor and end by analysing its renormalised expectation value at finite temperatures

A comparative analysis of juggling skill between Sepak raga and Bulu ayam

The uses of sepak takraw’s ball for daily training for children might cause injury, while contact between the foot and ball due to hard and heavy structure. This study aims to examine the differences of kinematic juggling between sepak raga and bulu ayam. Eight participants within the age 13.63 (±0.52) years old were asked to perform 20 trials of sepak sila and sepak kuda juggling using raga ball and bulu ayam. Digital Motion Analysis software was used to analyze the kinematics parameters. One-way repeated measure ANOVA was implemented to examine the differences between the sepak raga and bulu ayam. The finding shows that there are no significant differences of kinematic juggling between sepak raga and bulu ayam in sepak sila juggling skills as well as sepak kuda juggling skills (p > 0.05). The young athlete could choose either raga ball or bulu ayam for skill acquisition depending on their comfort

Not all adiabatic vacua are physical states

Adiabatic vacua are known to be Hadamard states. We show, however that the energy-momentum tensor of a linear Klein-Gordon field on Robertson-Walker spaces developes a generic singularity on the initial hypersurface if the adiabatic vacuum is of order less than four. Therefore, adiabatic vacua are physically reasonable only if their order is at least four. A certain non-local large momentum expansion of the mode functions has recently been suggested to yield the subtraction terms needed to remove the ultraviolet divergences in the energy-momentum tensor. We find that this scheme fails to reproduce the trace anomaly and therefore is not equivalent to adiabatic regularisation.Comment: 13 pages, LaTex2

Vlasov simulations of electron acceleration by radio frequency heating near the upper hybrid layer

It is shown by using a combination of Vlasov and test particles simulations that the electron distribution function resulting from energization due to Upper Hybrid (UH) plasma turbulence depends critically on the closeness of the pump wave to the double resonance, defined as omega≈omega_UH≈n omega_ce where n is an integer. For pump frequencies, away from the double resonance the electron distribution function is very close to Maxwellian, while as the pump frequency approaches the double resonance it develops a high energy tail. The simulations show turbulence involving coupling between Lower Hybrid (LH) and UH waves, followed by excitation of Electron Bernstein (EB) modes. For the particular case of a pump with frequency between n=3 and n=4 the EB modes cover the range from the first to the 5th mode. The simulations show that when the injected wave frequency is between the 3rd and 4th electron cyclotron frequency, bulk electron heating occurs due to the interaction between the electrons and large amplitude EB waves, primarily on the first EB branch leading to an essentially thermal distribution. On the other hand, when the frequency is slightly above the 4th electron cyclotron harmonic, the resonant interaction is predominantly due to the UH branch and leads to a further acceleration of high-velocity electrons and a distribution function with a suprathermal tail of energetic electrons. The results are consistent with ionospheric experiments and relevant to the production of Artificial Ionospheric Plasma Layers

Attractor states and infrared scaling in de Sitter space

The renormalized expectation value of the energy-momentum tensor for a scalar field with any mass m and curvature coupling xi is studied for an arbitrary homogeneous and isotropic physical initial state in de Sitter spacetime. We prove quite generally that has a fixed point attractor behavior at late times, which depends only on m and xi, for any fourth order adiabatic state that is infrared finite. Specifically, when m^2 + xi R > 0, approaches the Bunch-Davies de Sitter invariant value at late times, independently of the initial state. When m = xi = 0, it approaches instead the de Sitter invariant Allen-Folacci value. When m = 0 and xi \ge 0 we show that this state independent asymptotic value of the energy-momentum tensor is proportional to the conserved geometrical tensor (3)H_{ab}, which is related to the behavior of the quantum effective action of the scalar field under global Weyl rescaling. This relationship serves to generalize the definition of the trace anomaly in the infrared for massless, non-conformal fields. In the case m^2 + xi R = 0, but m and xi separately different from zero, grows linearly with cosmic time at late times. For most values of m and xi in the tachyonic cases, m^2 + xi R grows exponentially at late cosmic times for all physically admissable initial states.Comment: 30 pages, 6 figures, 46 kB tar.gz fil