7,796 research outputs found
Topological invariants for holographic semimetals
We study the behavior of fermion spectral functions for the holographic
topological Weyl and nodal line semimetals. We calculate the topological
invariants from the Green functions of both holographic semimetals using the
topological Hamiltonian method, which calculates topological invariants of
strongly interacting systems from an effective Hamiltonian system with the same
topological structure. Nontrivial topological invariants for both systems have
been obtained and the presence of nontrivial topological invariants further
supports the topological nature of the holographic semimetals.Comment: 39 pages, 11 figures, 1 table; v2: match published versio
Topological nodal line semimetals in holography
We show a holographic model of a strongly coupled topological nodal line
semimetal (NLSM) and find that the NLSM phase could go through a quantum phase
transition to a topologically trivial state. The dual fermion spectral function
shows that there are multiple Fermi surfaces each of which is a closed nodal
loop in the NLSM phase. The topological structure in the bulk is induced by the
IR interplay between the dual mass operator and the operator that deforms the
topology of the Fermi surface. We propose a practical framework for building
various strongly coupled topological semimetals in holography, which indicates
that at strong coupling topologically nontrivial semimetal states generally
exist.Comment: 21 pages, 5 figures; v2: match published versio
A Kinetic Model for Cell Damage Caused by Oligomer Formation
It is well-known that the formation of amyloid fiber may cause invertible
damage to cells, while the underlying mechanism has not been fully uncovered.
In this paper, we construct a mathematical model, consisting of infinite ODEs
in the form of mass-action equations together with two reaction-convection
PDEs, and then simplify it to a system of 5 ODEs by using the maximum entropy
principle. This model is based on four simple assumptions, one of which is that
cell damage is raised by oligomers rather than mature fibrils. With the
simplified model, the effects of nucleation and elongation, fragmentation,
protein and seeds concentrations on amyloid formation and cell damage are
extensively explored and compared with experiments. We hope that our results
can provide a valuable insight into the processes of amyloid formation and cell
damage thus raised.Comment: 16 pages+ 5 figures for maintext; 8 pages+ 4 figures for Supporting
Material
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