arXiv subjects
Publications and source records attributed to Osamu Narikiyo.
A diagrammatic approach based on thermal Green function to superconducting fluctuation transport is reviewed keeping consistency with Ginzburg-Landau theory. The correct expression of the heat current vertex for Cooper pairs is clarified via Jonson-Mahan formula and Ward identities.
A diagrammatic approach based on thermal Green function to superconducting fluctuation transport is reviewed focusing on Hall and Nernst effects. The treatment of weak magnetic field is carefully discussed within the linear order perturbation. In the Appendix the linear response theory for the DC Hall conductivity of the Dirac fermion in 2+1 space-time dimensions is reviewed. One focus is the Chern-Simons effective action for the gauge field. Another is the exact formula by Ishikawa and Matsuyama.
The weak-field Hall conductivity in metals is interpreted in terms of the curvature of the Fermi surface in the main part. In the appendix the orbital magnetic-susceptibility and the magneto-conductivity in metals are discussed focusing on Peierls' area factor.
The Tsuji formula which relates the Fermi-surface curvature and the weak-field Hall conductivity in metals is discussed in Haldane's framework.
The effect of the collision term of the Boltzmann equation is discussed for the diagonal conductivity in the absence of magnetic field and the off-diagonal conductivity within the linear order of magnetic field. The consistency between the Boltzmann equation and the Fermi-liquid theory is confirmed. The electron-electron interaction is totally taken into account via the self-energy of the electron. The Umklappness is taken into account as the geometrical factor. The current-vertex correction in the fluctuation-exchange (FLEX) approximation violates these conventional schemes. In the Appendix the Tsuji formula, the geometrical formula for the Hall conductivity is discussed.
We discuss the relation between entropic uncertainty relations by Buscemi et al. and by Barchielli et al.
Using a model spectral function of the electron the Hall conductivity in the normal metallic state of the Pr_{2-x}Ce_xCuO_4 (PCCO) superconductor is calculated neglecting the current vertex-correction. The result is qualitatively consistent with the experiment. Consequently the reason becomes clear why the Fermi-liquid theory fails to explain the anomaly of the Hall conductivity. The inconsistency of the fluctuation-exchange approximation also becomes clear.
The Ward identities for the charge and heat currents are derived for particle-particle and particle-hole pairs. They are the exact constraints on the current-vertex functions imposed by conservation laws and should be satisfied by consistent theories. While the Ward identity for the charge current of electrons is well established, that for the heat current is not understood correctly. Thus the correct interpretation is presented. On this firm basis the Ward identities for pairs are discussed. As the application of the identity we criticize some inconsistent results in the studies of the superconducting fluctuation transport and the transport anomaly in the normal state of high-Tc superconductors.
Using a series of computer simulations we have demonstrated a scenario of the early evolution of the bird-type primitive language. We do not assume wise agents who can use a grammar and manage an evolution without a grammar. Duplication and mutation of phrases is our strategy. Such a strategy is seen in wide classes of living phenomena.
Formal but exact DC conductivity formulae for anisotropic Fermi liquids are reviewed. One is the Maebashi-Fukuyama formula based on the Fermi-surface harmonics. The other is the Taylor formula based on the scattering eigenfunction. In comparison to these two formulae the current-vertex-correction in the fluctuation-exchange approximation is shown to be a bad vision caused by an inconsistent approximation.
The minimal requirements for life are autopoiesis and cognition. We propose autopoietic models with cognition and perform three classes of evolutionary simulation. In our models the plasticity of the metabolic cycle and the regulation function of the membrane are the bases for the cognition. The cognitive cells show the adaptation and the evolution. The environment also shows the evolution via the interaction with the system of cells. This is a prototype of the co-evolution of the living system and its environment.
We propose a physical model for developmental process at cellular level to discuss the mechanism of epigenetic landscape. In our simplified model, a minimal model, the network of the interaction among cells generates the landscape epigenetically and the differentiation in developmental process is understood as a self-organization. The effect of the regulation by gene expression which is a key ingredient in development is renormalized into the interaction and the environment. At earlier stage of the development the energy landscape of the model is rugged with small amplitude. The state of cells in such a landscape is susceptible to fluctuations and not uniquely determined. These cells are regarded as stem cells. At later stage of the development the landscape has a funnel-like structure corresponding to the canalization in differentiation. The rewinding or stability of the differentiation is also demonstrated by substituting test cells into the time sequence of the model development.
The Ward identity for the heat current vertex is illustrated in terms of Feynman diagrams. The Jonson-Mahan transmutation, the way how the kinetic energy at the heat current vertex for the free propagator is transmuted into the frequency for the full propagator, is the key of the illustration.
A mechanism of the translation in oligomer world is proposed. The translation is carried out by a minimum cycle, which is sustained by adaptors and helicases, and the first information processing in oligomer world. We expect that such a cycle actually worked in a primitive cell and can be constructed in vitro. By computer simulation we have shown that a proofreading is achieved by the fluctuation in the cell. It is rather paradoxical that the proofreading is effective for the system consisting of molecular machines with low efficiency.
A mechanism of the replication of proto-RNAs in oligomer world is proposed. The replication is carried out by a minimum cycle which is sustained by a ligase and a helicase. We expect that such a cycle actually worked in the primordial soup and can be constructed in vitro. By computer simulation the products of the replication acquires diversity and complexity. Such diversity and complexity are the bases of the evolution.
The vertex correction for the electric current is discussed on the basis of the Fermi-liquid theory. It does not alter the qualitative description of the electric transport by the relaxation-time approximation in the case of the normal state of high-Tc superconductors. The failure of the transport theory employing the fluctuation-exchange (FLEX) approximation is pointed out. It becomes manifest by considering the Ward identity for the fluctuation mode.
Ward identities for extended objects are discussed. In the limit of dc transport it is rigorously proved that charge-density and spin-density fluctuations do not couple to electromagnetic field.
Based on the oligomer-world hypothesis we propose an abstract model where the molecular recognition among oligomers is described in the shape space. The origin of life in the oligomer world is regarded as the establishment of a metabolic cycle in a primitive cell. The cycle is sustained by the molecular recognition. If an original cell acquires the ability of the replication of oligomers, the relationship among oligomers changes due to the poor fidelity of the replication. This change leads to the diversification of metabolic cycles. The selection among diverse cycles is the basis of the evolution. The evolvability is one of the essential characters of life. We demonstrate the origin and diversification of the metabolic cycle by the computer simulation of our model. Such a simulation is expected to be the simplified demonstration of what actually occurred in the primordial soup. Our model describes an analog era preceding the digital era based on the genetic code.