Higuchi, Atsushi, Lee, Yen Cheong, Nicholas, Jack R.
In a recent paper (Phys. Rev. D78, 084031 (2008), arXiv:0808.0642, Ref. [1]) it was shown in examples that the covariant retarded Green's functions in particular gauges for electromagnetism and...
Higuchi, Atsushi, Lee, Yen Cheong
We study conformally-coupled massive scalar field theory with the mass term treated as a perturbation in the expanding half of de Sitter spacetime as a toy model for comparing various perturbative...
A free-theory vacuum state of an interacting field theory, e.g. quantum gravity, is unstable at tree level in general due to spontaneous emission of Fock-space particles in any spacetime with no...
How to use retarded Green's functions in de Sitter spacetime (2008)
Higuchi, Atsushi, Lee, Yen Cheong
We demonstrate in examples that the covariant retarded Green's functions in electromagnetism and linearized gravity work as expected in de Sitter spacetime. We first clarify how retarded Green's...
The propagators of the Faddeev-Popov (FP) ghosts for Yang-Mills theories and perturbative quantum gravity in the covariant gauge are infrared (IR) divergent in de Sitter spacetime. We point out,...
Takayuki Shiose, Takashi Yamanaka, Atsushi Higuchi
Abstract. In a design situation, it is said that the emergence of a
Topological censorship and chronology protection (2008)
Friedman, John L., Higuchi, Atsushi
Over the past two decades, substantial efforts have been made to understand the way in which physics enforces the ordinary topology and causal structure that we observe, from subnuclear to...
Atsushi Higuchi, Daniel Sudarsky
We show that static sources coupled to a massless scalar field in Schwarzschild spacetime give rise to emission and absorption of zero-energy particles due to the presence of Hawking radiation. This...
The Unruh effect and its applications (2007)
Crispino, Luis C. B., Higuchi, Atsushi, Matsas, George E. A.
It has been thirty years since the discovery of the Unruh effect. It has played a crucial role in our understanding that the particle content of a field theory is observer dependent. This effect is...
On maximal entanglement between two pairs in four-qubit pure states (2007)
Brierley, Stephen, Higuchi, Atsushi
We show that the state with the highest known average two-particle von Neumann entanglement entropy proposed by Sudbery and one of the authors gives a local maximum of this entropy. We also show that...
Quantum Radiation Reaction and the Green's Function Decomposition (2006)
Higuchi, Atsushi, Martin, Giles D. R.
We analyze the change in position (the position shift) of the wave packet of a charged scalar particle due to radiation reaction in the $\hbar \to 0$ limit of quantum electrodynamics. In particular,...
Possible Constraints on String Theory in Closed Space with Symmetries (2005)
It is well known that certain quadratic constraints have to be imposed on linearized gravity in closed space with symmetries. We review this phenomenon and discuss one of the constraints which arise...
Higuchi, Atsushi, Martin, Giles D. R.
We extend our previous work (see arXiv:quant-ph/0501026), which compared the predictions of quantum electrodynamics concerning radiation reaction with those of the Abraham-Lorentz-Dirac theory for a...
Classical and quantum radiation reaction for linear acceleration (2005)
Higuchi, Atsushi, Martin, Giles D. R.
We investigate the effect of radiation reaction on the motion of a wave packet of a charged scalar particle linearly accelerated in quantum electrodynamics. We give the details of the calculations...
Crispino, Luis C. B., Higuchi, Atsushi, Matsas, George E. A.
It was shown recently that in four dimensions scalar sources with fixed proper acceleration minimally coupled to a massless Klein-Gordon field lead to the same responses when they are (i) uniformly...
The Lorentz-Dirac force from QED for linear acceleration (2004)
Higuchi, Atsushi, Martin, Giles D. R.
We investigate the motion of a wave packet of a charged scalar particle linearly accelerated by a static potential in quantum electrodynamics. We calculate the expectation value of the position of...
On the one-particle reduced density matrices of a pure three-qutrit quantum state (2003)
We present a necessary and sufficient condition for three qutrit density matrices to be the one-particle reduced density matrices of a pure three-qutrit quantum state. The condition consists of seven...
The physical graviton two-point function in de Sitter spacetime with S^3 spatial sections (2002)
Higuchi, Atsushi, Weeks, Richard H.
We compute the physical graviton two-point function in de Sitter spacetime with three-sphere spatial sections. We demonstrate that the large-distance growth present in the corresponding two-point...
Radiation reaction in quantum field theory (2002)
We investigate radiation-reaction effects for a charged scalar particle accelerated by an external potential realized as a space-dependent mass term in quantum electrodynamics. In particular, we...
Low-frequency scalar absorption cross sections for stationary black holes (2001)
We discuss the absorption cross section for the minimally-coupled massless scalar field into a stationary and circularly symmetric black hole with nonzero angular velocity in four or higher...
The covariant graviton propagator in de Sitter spacetime (2001)
Higuchi, Atsushi, Kouris, Spyros S.
We consider the covariant graviton propagator in de Sitter spacetime in a gauge with two parameters, alpha and beta, in the Euclidean approach. We give an explicit form of the propagator with a...
On the scalar sector of the covariant graviton two-point function in de Sitter spacetime (2000)
Higuchi, Atsushi, Kouris, Spyros S.
We examine the scalar sector of the covariant graviton two-point function in de Sitter spacetime. This sector consists of the pure-trace part and another part described by a scalar field. We show...
Scalar radiation emitted from a source rotating around a black hole (1999)
Crispino, Luis C. B., Higuchi, Atsushi, Matsas, George E. A.
We analyze the scalar radiation emitted from a source rotating around a Schwarzschild black hole using the framework of quantum field theory at the tree level. We show that for relativistic circular...
Radiation reaction in quantum mechanics (1998)
The Lorentz-Dirac radiation reaction formula predicts that the position shift of a charged particle due to the radiation reaction is of first order in acceleration if it undergoes a small...
Interaction of Hawking radiation with static sources outside a Schwarzschild black hole (1998)
Higuchi, Atsushi, Matsas, George E. A., Sudarsky, Daniel
We show that the response rate of (i) a static source interacting with Hawking radiation of massless scalar field in Schwarzschild spacetime (with the Unruh vacuum) and that of (ii) a uniformly...
Interaction of Hawking radiation and a static electric charge (1998)
Crispino, Luis C. B., Higuchi, Atsushi, Matsas, George E. A.
We investigate whether the equality found for the response of static scalar sources interacting (i) with {\em Hawking radiation in Schwarzschild spacetime} and (ii) with the Fulling-Davies-Unruh...
Quantum field theory in Lorentzian universes-from-nothing (1995)
Friedman, John L., Higuchi, Atsushi
We examine quantum field theory in spacetimes that are time nonorientable but have no other causal pathology. These are Lorentzian universes-from-nothing, spacetimes with a single spacelike boundary...
On the eigenfunctions of the Dirac operator on spheres and real hyperbolic spaces (1995)
Roberto Camporesi, Atsushi Higuchi
The eigenfunctions of the Dirac operator on spheres and real hyperbolic spaces of arbitrary dimension are computed by separating variables in geodesic polar coordinates. These eigenfunctions are used...
Quantum field theory in Lorentzian universes-from-nothing (1994)
John L. Friedman, Atsushi Higuchi
We examine quantum field theory in spacetimes that are time nonorientable but have no other causal pathology. These are Lorentzian universesfrom -nothing, spacetimes with a single spacelike boundary...
樋口, 篤志, ヒグチ, アツシ, Higuchi, Atsushi, Tetsuya, Hiyama
名古屋大学地球水循環研究センター衛星気象学研究室[中村研]助手樋口篤志のホームページ。履歴書、研究テーマ、観測日記、論文リストなど。
近藤, 昭彦, コンドウ, アキヒコ, Kondō, Akihiko, 樋口, 篤志, ヒグチ, アツシ, Higuchi, Atsushi
研究概要:本論では連続して撮影された可視・近赤外リモートセンシング画像から蒸発散量に関するシグナルの抽出を試みた。観測地は筑波大学水理...
PGLIERC (Preliminary GLobal Imager experiment at Environmental Research Center) : その概要
西田, 顕郎, 飯田, 真一, 新村, 典子, 近藤, 昭彦, コンドウ, アキヒコ, Kondō, Akihiko, ...
研究概要:リモートセンシング技術の水文学への応用はこれまで多く行われてきている.本研究では来年打ち上げ予定のADEOS-II/GLIに注目し,水文・リモ...
Monitoring the Drying Process Using Multi-Temporal AVHRR Data in 1990, Huaihe River Basin, China
樋口, 篤志, Higuchi, Atsushi, 近藤, 昭彦, Kondoh, Akihiko, Kishi, Shinkichi, Fukuzono, Teruki, ...
研究概要:Recent researches have shown that the combination of spectral vegetation indices (VIs) with thermal infrared observations may provide an effective method for parameterizing surface...
近藤, 昭彦, コンドウ, アキヒコ, Kondō, Akihiko, 樋口, 篤志, ヒグチ, アツシ, Higuchi, Atsushi
研究概要:本論では連続して撮影された可視・近赤外リモートセンシング画像から蒸発散量に関するシグナルの抽出を試みた。観測地は筑波大学水理...
PGLIERC (Preliminary GLobal Imager experiment at Environmental Research Center) : その概要
西田, 顕郎, 飯田, 真一, 新村, 典子, 近藤, 昭彦, コンドウ, アキヒコ, Kondō, Akihiko, ...
研究概要:リモートセンシング技術の水文学への応用はこれまで多く行われてきている.本研究では来年打ち上げ予定のADEOS-II/GLIに注目し,水文・リモ...
Monitoring the Drying Process Using Multi-Temporal AVHRR Data in 1990, Huaihe River Basin, China
樋口, 篤志, Higuchi, Atsushi, 近藤, 昭彦, Kondoh, Akihiko, Kishi, Shinkichi, Fukuzono, Teruki, ...
研究概要:Recent researches have shown that the combination of spectral vegetation indices (VIs) with thermal infrared observations may provide an effective method for parameterizing surface...
樋口, 篤志, ヒグチ, アツシ, Higuchi, Atsushi, Tetsuya, Hiyama
名古屋大学地球水循環研究センター衛星気象学研究室[中村研]助手樋口篤志のホームページ。履歴書、研究テーマ、観測日記、論文リストなど。
近藤, 昭彦, コンドウ, アキヒコ, Kondō, Akihiko, 樋口, 篤志, ヒグチ, アツシ, Higuchi, Atsushi
研究概要:本論では連続して撮影された可視・近赤外リモートセンシング画像から蒸発散量に関するシグナルの抽出を試みた。観測地は筑波大学水理...
PGLIERC (Preliminary GLobal Imager experiment at Environmental Research Center) : その概要
西田, 顕郎, 飯田, 真一, 新村, 典子, 近藤, 昭彦, コンドウ, アキヒコ, Kondō, Akihiko, ...
研究概要:リモートセンシング技術の水文学への応用はこれまで多く行われてきている.本研究では来年打ち上げ予定のADEOS-II/GLIに注目し,水文・リモ...
Monitoring the Drying Process Using Multi-Temporal AVHRR Data in 1990, Huaihe River Basin, China
樋口, 篤志, Higuchi, Atsushi, 近藤, 昭彦, Kondoh, Akihiko, Kishi, Shinkichi, Fukuzono, Teruki, ...
研究概要:Recent researches have shown that the combination of spectral vegetation indices (VIs) with thermal infrared observations may provide an effective method for parameterizing surface...
研究課題 葉面ワックスが可視・近赤外反射特性に与える影響に関する基礎研究
樋口, 篤志, ヒグチ, アツシ, Higuchi, Atsushi, 大田, 啓一, オオタ, ケイイチ, Ōta, Keīchi
近藤, 昭彦, 樋口, 篤志, ヒグチ, アツシ, Higuchi, Atsushi
1.3.7.地理情報システムを用いた流域水文情報の抽出法に関する研究(1.3データベース研究部門)([1]研究活動)
可視・近赤外衛星画像の時系列データと地上における水文・植生状態量, フラックスとの関係
近藤, 昭彦, 樋口, 篤志, ヒグチ, アツシ, Higuchi, Atsushi, 池田, 正一, 黒子, 裕史
1.3データベース研究部門 1.3.1.
可視・近赤外衛星画像の時系列データと地上における水文・植生状態量, フラックスとの関係(継続)
樋口, 篤志, ヒグチ, アツシ, Higuchi, Atsushi, 西田, 顕郎, 飯田, 真一, 新村, 典子, ...
1.3データベース研究部門 1.3.1
1.3.1可視・近赤外衛星画像の時系列データと地上における水文・植生状態量, フラックスとの関係(継続)(1.3データベース研究部門)([1]研究活動)
樋口, 篤志, ヒグチ, アツシ, Higuchi, Atsushi, 西田, 顕郎, 飯田, 真一, 新村, 典子, ...
Bremsstrahlung By Static Charges Outside a Static Black Hole ?
Daniel Sudarsky, Atsushi Higuchi
We show that in complete analogy with the usual bremsstrahlung process, when studied from the coaccelerated observer's point of view, a charge moving along the integral curves of the static...