37,756 research outputs found
Incorporating prior financial domain knowledge into neural networks for implied volatility surface prediction
In this paper we develop a novel neural network model for predicting implied
volatility surface. Prior financial domain knowledge is taken into account. A
new activation function that incorporates volatility smile is proposed, which
is used for the hidden nodes that process the underlying asset price. In
addition, financial conditions, such as the absence of arbitrage, the
boundaries and the asymptotic slope, are embedded into the loss function. This
is one of the very first studies which discuss a methodological framework that
incorporates prior financial domain knowledge into neural network architecture
design and model training. The proposed model outperforms the benchmarked
models with the option data on the S&P 500 index over 20 years. More
importantly, the domain knowledge is satisfied empirically, showing the model
is consistent with the existing financial theories and conditions related to
implied volatility surface.Comment: 8 pages, SIGKDD 202
Detecting fractional Josephson effect through phase slip
Fractional Josephson effect is a unique character of Majorana Fermions in
topological superconductor system. This effect is very difficult to detect
experimentally because of the disturbance of quasiparticle poisoning and
unwanted couplings in the superconductor. Here, we propose a scheme to probe
fractional DC Josephson effect of semiconductor nanowire-based topological
Josephson junction through 4{\pi} phase slip. By exploiting a topological RF
SQUID system we find that the dominant contribution for Josephson coupling
comes from the interaction of Majorana Fermions, resulting the resonant
tunneling with 4{\pi} phase slip. Our calculations with experimentally
reachable parameters show that the time scale for detecting the phase slip is
two orders of magnitude shorter than the poisoning time of nonequilibrium
quasiparticles. Additionally, with a reasonable nanowire length the 4{\pi}
phase slip could overwhelm the topological trivial 2{\pi} phase slip. Our work
is meaningful for exploring the effect of modest quantum fluctuations of the
phase of the superconductor on the topological system, and provide a new method
for quantum information processing.Comment: 5 pages, 3 figure
Detecting fractional Josephson effect through phase slip
Fractional Josephson effect is a unique character of Majorana Fermions in
topological superconductor system. This effect is very difficult to detect
experimentally because of the disturbance of quasiparticle poisoning and
unwanted couplings in the superconductor. Here, we propose a scheme to probe
fractional DC Josephson effect of semiconductor nanowire-based topological
Josephson junction through 4{\pi} phase slip. By exploiting a topological RF
SQUID system we find that the dominant contribution for Josephson coupling
comes from the interaction of Majorana Fermions, resulting the resonant
tunneling with 4{\pi} phase slip. Our calculations with experimentally
reachable parameters show that the time scale for detecting the phase slip is
two orders of magnitude shorter than the poisoning time of nonequilibrium
quasiparticles. Additionally, with a reasonable nanowire length the 4{\pi}
phase slip could overwhelm the topological trivial 2{\pi} phase slip. Our work
is meaningful for exploring the effect of modest quantum fluctuations of the
phase of the superconductor on the topological system, and provide a new method
for quantum information processing.Comment: 5 pages, 3 figure
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