3,974 research outputs found
Product Hardy spaces associated to operators with heat kernel bounds on spaces of homogeneous type
The aim of this article is to develop the theory of product Hardy spaces
associated with operators which possess the weak assumption of Davies--Gaffney
heat kernel estimates, in the setting of spaces of homogeneous type. We also
establish a Calder\'on--Zygmund decomposition on product spaces, which is of
independent interest, and use it to study the interpolation of these product
Hardy spaces. We then show that under the assumption of generalized Gaussian
estimates, the product Hardy spaces coincide with the Lebesgue spaces, for an
appropriate range of~.Comment: Accepted by Math.
Sublattice-sensitive Majorana Modes
For two- and three-dimensional topological insulators whose unit cells
consist of multiple sublattices, the boundary terminating at which type of
sublattice can affect the time-reversal invariant momentum at which the Dirac
points of helical boundary states are located. Through a general theory and a
representative model, we reveal that this interesting property allows the
realization of Majorana modes at sublattice domain walls forming on the
boundary when the boundary Dirac points of the topological insulator are gapped
by an unconventional superconductor in proximity. Intriguingly, we find that
the sensitive sublattice-dependence of the Majorana modes allows their
positions to be precisely manipulated by locally controlling the terminating
sublattices or boundary potential. Our work reveals that the common sublattice
degrees of freedom in materials open a new route to realize and manipulate
Majorana modes.Comment: 21 pages,10 figure
Variability in the impacts of partisan conflict: a new perspective from bank credit
The purpose of this article is to analyse the impact of partisan conflict
on bank credit, and take the global financial crisis as the time
node to analyse the variability of this impact before and after the
financial crisis. This article examines the impacts of partisan conflict
on the bank credit by employing the US data covering the past
40 years and captures the variability in the effects of partisan conflict
based on the rolling sample and time-varying parameter VAR
analysis. The full sample results reveal that one standard deviation
partisan conflict shock will shrink the bank credit growth rate to
nonfinancial sectors, and the negative effects of partisan conflict on
bank credit are more substantial after the global financial crisis. The
rolling sample and time-varying parameter VAR analysis further confirm
that the impacts of partisan conflict shock have varied substantially
over time, where bank credit still negatively reacts to the
impacts of partisan conflict in recent periods. Additionally, we estimate
two extended models and support the intermediate role of
economic policy uncertainty in transmitting the partisan conflict
and the substitution effect of cross-border bank lending on domestic
bank credit. Finally, our major results are unchanged by performing
a series of robustness checks. The conclusion of this article is
that partisan conflict has a significant impact on bank credit and
shows obvious variability, which is more significant after the global
financial crisis
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