Apparent superluminal separation velocities of the components of extragalactic objects

Matveenko, L. I.

doi:10.1070/pu1983v026n07abeh004451

Cited by 7 publications

(8 citation statements)

References 3 publications

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“…Hence the torsion nature of polarons which is rarely recognized. [31][32][33] The polaronic effect strongly reduces the mobility of charge carriers, hence a practical recommendation to lock the libronic degrees of freedom, as it happens in ladder-type polymers. If the carriers in polymers are indeed the intra-monomer polarons, then the low mobility would eliminate advantages with respect to molecular crystals used in OLEDs and the materials lose their attractiveness in applications.…”

Section: Polarons-another Semantic Problemmentioning

confidence: 99%

Physical theory of excitons in conducting polymers

2010

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In this tutorial review, we cover the solid state physics approach to electronic and optical properties of conducting polymers. We attempt to bring together languages and advantages of the solid state theory for polymers and of the quantum chemistry for monomers. We consider polymers as generic one-dimensional semiconductors with features of strongly correlated electronic systems. Our model combines the long range electron-hole Coulomb attraction with a specific effect of strong intra-monomer electronic correlations, which results in effective intra-monomer electron-hole repulsion. Our approach allows to go beyond the single-chain picture and to compare excitons for polymers in solutions and in films. The approach helps connecting such different questions as shallow singlet and deep triplet excitons, stronger binding of interchain excitons in films, crossings of excitons' branches, 1/N energies shifts in oligomers. We describe a strong suppression of the luminescence from free charge carriers by long-range Coulomb interactions. Main attention is devoted to the most requested in applications phenyl based polymers. The specifics of the benzene ring monomer give rise to existence of three possible types of excitons: Wannier-Mott, Frenkel and intermediate ones. We discuss experimental manifestations of various excitons and of their transformations. We touch effects of the time-resolved self-trapping by libron modes leading to formation of torsion polarons.

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Section: Polarons-another Semantic Problemmentioning

confidence: 99%

Physical theory of excitons in conducting polymers

2010

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“…The cross section for reaction (6) was computed by Matveenko (1974) and Hunter & Kuriyan (1977) for energies from 10 −3 to 7.5 eV. The two results differ by a factor ∼ 2 at low energies for reasons unclear.…”

Section: Chemical Reactionsmentioning

confidence: 99%

Deuterium chemistry in the primordial gas

Galli

Palla

2002

Planetary and Space Science

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We review and update some aspects of deuterium chemistry in the postrecombination Universe with particular emphasis on the formation and destruction of HD. We examine in detail the available theoretical and experimental data for the leading reactions of deuterium chemistry and we highlight the areas where improvements in the determination of rate coefficients are necessary to reduce the remaining uncertainties. We discuss the cooling properties of HD and the modifications to the standard cooling function introduced by the presence of the cosmological radiation field. Finally, we consider the effects of deuterium chemistry on the dynamical collapse of primordial clouds in a simple "top-hat" scenario, and we speculate on the minimum mass a cloud must have in order to be able to cool in a Hubble time.

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“…In a previous work we considered the finite-frequency charge conductivity of the Hubbard model [13]. Here we study the current expectation value in any energy eigenstate, extending the work presented in references [19,37,54] for states with c, γ > 0 occupancies. In this section we find, as in the case of the quasi-particles of a Fermi liquid, that the spectrum J ρ αγ (q)…”

Section: Charge-current Spectrummentioning

confidence: 80%

Charge and spin transport in the one-dimensional Hubbard model

Peres¹,

Sacramento²,

Carmelo³

2001

J. Phys.: Condens. Matter

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We study the charge and spin currents transported by the elementary excitations of the one-dimensional (1D) Hubbard model and derive the corresponding current spectra. We present results both for finite-size systems and in the thermodynamic limit. This includes finding the couplings of both the low-energy and finite-energy (string) excitations to external charge and spin probes. At zero magnetic field the general structure of the charge-spin separation survives at all energy scales and the effective charges of both the low-energy and finite-energy charge excitations are studied as functions of the on-site Coulomb interaction U, electronic density n, and applied magnetic field H. In some limits the effective charge of the low-energy excitations equals that of the electrons, whereas that of the finite-energy charge-string excitations of rapidity length γ is found to be 2γ times the electronic charge. At U = ∞ the spin excitations do not contribute to spin transport, whereas the low-energy charge excitations feel an effective flux given by (ϕ↑N↑-ϕ↓N↓)/(N↑ + N↓), where Nσ is the number of electrons of spin σ and ϕσ is a spin-dependent flux. This reveals that at zero magnetic field and U = ∞ there is no spin transport, while at finite magnetic field the low-energy charge excitations also carry spin. In the U>>t limit the spin is carried both by holons and spinons. Finally, we find that the charge- and spin-current spectra can be derived from a semi-classical approach.

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Apparent superluminal separation velocities of the components of extragalactic objects

Cited by 7 publications

References 3 publications

Physical theory of excitons in conducting polymers

Physical theory of excitons in conducting polymers

Deuterium chemistry in the primordial gas

Charge and spin transport in the one-dimensional Hubbard model

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