activity
20102024
most citedForecast constraints on cosmic string parameters from gravitational wave direct detection experiments

67 citations · 355 across the 27 of their papers we have counts for

collaborators

27 papers

quant-ph2024★ 1 cited

Quantum algorithm for copula-based risk aggregation using orthogonal series density estimation

Hitomi Mori, Koichi Miyamoto

Quantum Monte Carlo integration (QMCI) provides a quadratic speed-up over its classical counterpart, and its applications have been investigated in various fields, including financ…

quant-ph2023

On the bias in iterative quantum amplitude estimation

Koichi Miyamoto

Quantum amplitude estimation (QAE) is a pivotal quantum algorithm to estimate the squared amplitude of the target basis state in a quantum state . Various improvemen…

quant-ph2023★ 24 cited

A comprehensive survey on quantum computer usage: How many qubits are employed for what purposes?

Tsubasa Ichikawa, Hideaki Hakoshima, Koji Inui +18

Quantum computers (QCs), which work based on the law of quantum mechanics, are expected to be faster than classical computers in several computational tasks such as prime factoring…

cs.LG2023★ 8 cited

The cross-sectional stock return predictions via quantum neural network and tensor network

Nozomu Kobayashi, Yoshiyuki Suimon, Koichi Miyamoto +1

In this paper, we investigate the application of quantum and quantum-inspired machine learning algorithms to stock return predictions. Specifically, we evaluate the performance of…

quant-ph2023

Quantum Metropolis-Hastings algorithm with the target distribution calculated by quantum Monte Carlo integration

Koichi Miyamoto

The Markov chain Monte Carlo method (MCMC), especially the Metropolis-Hastings (MH) algorithm, is a widely used technique for sampling from a target probability distribution on…

quant-ph2023

Quantum algorithm for position weight matrix matching

Koichi Miyamoto, Naoki Yamamoto, Yasubumi Sakakibara

We propose two quantum algorithms for a problem in bioinformatics, position weight matrix (PWM) matching, which aims to find segments (sequence motifs) in a biological sequence suc…

quant-ph2022

Extracting a function encoded in amplitudes of a quantum state by tensor network and orthogonal function expansion

Koichi Miyamoto, Hiroshi Ueda

There are quantum algorithms for finding a function satisfying a set of conditions, such as solving partial differential equations, and these achieve exponential quantum speedu…

quant-ph2022★ 1 cited

Pricing multi-asset derivatives by variational quantum algorithms

Kenji Kubo, Koichi Miyamoto, Kosuke Mitarai +1

Pricing a multi-asset derivative is an important problem in financial engineering, both theoretically and practically. Although it is suitable to numerically solve partial differen…

astro-ph.IM2022

Gravitational wave matched filtering by quantum Monte Carlo integration and quantum amplitude amplification

Koichi Miyamoto, Gonzalo Morrás, Takahiro S. Yamamoto +2

The speedup of heavy numerical tasks by quantum computing is now actively investigated in various fields including data analysis in physics and astronomy. In this paper, we propose…

quant-ph2022★ 4 cited

Quantum algorithm for calculating risk contributions in a credit portfolio

Koichi Miyamoto

Finance is one of the promising field for industrial application of quantum computing. In particular, quantum algorithms for calculation of risk measures such as the value at risk…

quant-ph2021

Quantum algorithms for numerical differentiation of expected values with respect to parameters

Koichi Miyamoto

The quantum algorithms for Monte Carlo integration (QMCI), which are based on quantum amplitude estimation (QAE), speed up expected value calculation compared with classical counte…

quant-ph2021★ 5 cited

Pricing multi-asset derivatives by finite difference method on a quantum computer

Koichi Miyamoto, Kenji Kubo

Following the recent great advance of quantum computing technology, there are growing interests in its applications to industries, including finance. In this paper, we focus on der…

quant-ph2021

Bermudan option pricing by quantum amplitude estimation and Chebyshev interpolation

Koichi Miyamoto

Pricing of financial derivatives, in particular early exercisable options such as Bermudan options, is an important but heavy numerical task in financial institutions, and its spee…

quant-ph2021★ 7 cited

Linear Regression by Quantum Amplitude Estimation and its Extension to Convex Optimization

Kazuya Kaneko, Koichi Miyamoto, Naoyuki Takeda +1

Linear regression is a basic and widely-used methodology in data analysis. It is known that some quantum algorithms efficiently perform least squares linear regression of an expone…

quant-ph2020

Quantum Speedup of Monte Carlo Integration with respect to the Number of Dimensions and its Application to Finance

Kazuya Kaneko, Koichi Miyamoto, Naoyuki Takeda +1

Monte Carlo integration using quantum computers has been widely investigated, including applications to concrete problems. It is known that quantum algorithms based on quantum ampl…

quant-ph2020★ 3 cited

Quantum Pricing with a Smile: Implementation of Local Volatility Model on Quantum Computer

Kazuya Kaneko, Koichi Miyamoto, Naoyuki Takeda +1

Applications of the quantum algorithm for Monte Carlo simulation to pricing of financial derivatives have been discussed in previous papers. However, up to now, the pricing model d…

quant-ph2019★ 36 cited

Reduction of Qubits in Quantum Algorithm for Monte Carlo Simulation by Pseudo-random Number Generator

Koichi Miyamoto, Kenji Shiohara

It is known that quantum computers can speed up Monte Carlo simulation compared to classical counterparts. There are already some proposals of application of the quantum algorithm…

astro-ph.CO2013★ 23 cited

CMB distortion anisotropies due to the decay of primordial magnetic fields

Koichi Miyamoto, Toyokazu Sekiguchi, Hiroyuki Tashiro +1

We investigate the power spectrum of the distortion of Cosmic Microwave Background (CMB) due to the decay of the primordial magnetic fields. It is known that there are two-types of…

astro-ph.CO2012★ 23 cited

Cosmological and astrophysical constraints on superconducting cosmic strings

Koichi Miyamoto, Kazunori Nakayama

We investigate the cosmological and astrophysical constraints on superconducting cosmic strings (SCSs). SCS loops emit strong bursts of electromagnetic waves, which might affect va…

astro-ph.CO2012★ 48 cited

Forecast constraints on cosmic strings from future CMB, pulsar timing and gravitational wave direct detection experiments

Sachiko Kuroyanagi, Koichi Miyamoto, Toyokazu Sekiguchi +2

We study future observational constraints on cosmic string parameters from various types of next-generation experiments: direct detection of gravitational waves (GWs), pulsar timin…

astro-ph.CO2012★ 21 cited

Non-Gaussian isocurvature perturbations in dark radiation

Etsuko Kawakami, Masahiro Kawasaki, Koichi Miyamoto +2

We study non-Gaussian properties of the isocurvature perturbations in the dark radiation, which consists of the active neutrinos and extra light species, if exist. We first derive…

astro-ph.CO2012★ 67 cited

Forecast constraints on cosmic string parameters from gravitational wave direct detection experiments

Sachiko Kuroyanagi, Koichi Miyamoto, Toyokazu Sekiguchi +2

Gravitational waves (GWs) are one of the key signatures of cosmic strings. If GWs from cosmic strings are detected in future experiments, not only their existence can be confirmed…

astro-ph.CO2011★ 24 cited

Isocurvature perturbations in extra radiation

Masahiro Kawasaki, Koichi Miyamoto, Kazunori Nakayama +1

Recent cosmological observations, including measurements of the CMB anisotropy and the primordial helium abundance, indicate the existence of an extra radiation component in the Un…

hep-ph2011★ 3 cited

Cosmological effects of decaying cosmic string loops with TeV scale width

Masahiro Kawasaki, Koichi Miyamoto, Kazunori Nakayama

In supersymmetric theories, cosmic strings produced in the early Universe often have a width of TeV scale, while the tension is much larger. In a scaling regime, an infinite cosmic…