English
Related papers

Related papers: Complex action suggests future-included theory

200 papers

We study a complex action theory (CAT) whose path runs over not only past but also future. We show that if we regard a matrix element defined in terms of the future state at time $T_B$ and the past state at time $T_A$ as an expectation…

Quantum Physics · Physics 2019-01-25 Keiichi Nagao , Holger Bech Nielsen

In the future-included real action theory whose path runs over not only past but also future, we demonstrate a theorem, which states that the normalized matrix element of a Hermitian operator $\hat{\cal O}$ defined in terms of the future…

Quantum Physics · Physics 2017-08-04 Keiichi Nagao , Holger Bech Nielsen

We briefly review the correspondence principle proposed in our previous paper, which claims that if we regard a matrix element defined in terms of the future state at time $T_B$ and the past state at time $T_A$ as an expectation value in…

Quantum Physics · Physics 2013-05-21 Keiichi Nagao , Holger Bech Nielsen

Studying the time development of the expectation value in the future-not-included complex action theory, we point out that the momentum relation (the relation analogous to $p=\frac{\partial L}{\partial \dot{q}}$), which was derived via the…

Quantum Physics · Physics 2019-01-28 Keiichi Nagao , Holger Bech Nielsen

In the future-included complex and real action theories whose paths run over not only the past but also the future, we briefly review the theorem on the normalized matrix element of an operator $\hat{\cal O}$, which is defined in terms of…

Quantum Physics · Physics 2017-10-06 Keiichi Nagao , Holger Bech Nielsen

We study the periodic complex action theory (CAT) by imposing a periodic condition in the future-included CAT where the time integration is performed from the past to the future, and extend a normalized matrix element of an operator…

Quantum Physics · Physics 2022-08-16 Keiichi Nagao , Holger Bech Nielsen

We propose a formulation of quantum mechanics in an extended Fock space in which a tensor product structure is applied to time. Subspaces of histories consistent with the dynamics of a particular theory are defined by a direct quantum…

Quantum Physics · Physics 2021-03-29 N. L. Diaz , J. M. Matera , R. Rossignoli

We develop some formalism which is very general Feynman path integral in the case of the action which is allowed to be complex. The major point is that the effect of the imaginary part of the action (mainly) is to determine which solution…

General Physics · Physics 2009-10-13 Holger B. Nielsen , Masaao Ninomiya

Imaginary time is often used in quantum tunnelling calculations. This article advocates a conceptually sounder alternative: complex lapse. In the ``3+1'' action for the Einstein gravitational field minimally coupled to a Klein-Gordon field,…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Sean A. Hayward

In the complex action theory whose path runs over not only past but also future we study a normalized matrix element of an operator $\hat{\cal O}$ defined in terms of the future state at the latest time $T_B$ and the past state at the…

Quantum Physics · Physics 2016-06-21 Keiichi Nagao , Holger Bech Nielsen

The Feynman path integral does not allow a "one real path" interpretation, because amplitudes contribute to probabilities in a non-separable manner. The opposite extreme, "all paths happen", is not a useful or informative account. In this…

Quantum Physics · Physics 2016-01-13 K. B. Wharton

A model -- by myself and Masao Ninomiya -- which in principle predicts the initial conditions in a way as to minimze a certain functional of the history of the Universe through both past and future -- a functional conceived of as an…

Quantum Physics · Physics 2009-11-23 H. B. Nielsen

The fundamental dynamics of quantum particles is neutral with respect to the arrow of time. And yet, our experiments are not: we observe quantum systems evolving from the past to the future, but not the other way round. A fundamental…

Quantum Physics · Physics 2022-11-01 Giulio Chiribella , Zixuan Liu

There exists a stark tension among different formulations of quantum theory as some are inherently time-symmetric while others are time-asymmetric. This tension is crisply captured when considering physical theories as theories of…

Quantum Physics · Physics 2024-11-12 John H. Selby , Maria E. Stasinou , Stefano Gogioso , Bob Coecke

The Feynman Path Integral is extended in order to capture all solutions of a quantum field theory. This is done via a choice of appropriate integration cycles, parametrized by M in SL(2,C), i.e., the space of allowed integration cycles is…

High Energy Physics - Theory · Physics 2015-03-13 D. D. Ferrante , G. S. Guralnik , Z. Guralnik , C. Pehlevan

Normally we quantize along the space dimensions but treat time classically. But from relativity we expect a high level of symmetry between time and space. What happens if we quantize time using the same rules we use to quantize space? To do…

Quantum Physics · Physics 2010-05-06 John Ashmead

This is a philosophical paper. It claims that there is a gap to be filled in the relationship between complexity theory (CT) and quantum theory (QT). This gap concerns two very distinct understandings of time. The paper provides the ground…

History and Philosophy of Physics · Physics 2016-11-23 Carlos Eduardo Maldonado

We formulate a complex action theory which includes operators of coordinate and momentum $\hat{q}$ and $\hat{p}$ being replaced with non-hermitian operators $\hat{q}_{new}$ and $\hat{p}_{new}$, and their eigenstates ${}_m <_{new} q |$ and…

Quantum Physics · Physics 2012-04-24 Keiichi Nagao , Holger Bech Nielsen

An analysis of classical mechanics in a complex extension of phase space shows that a particle in such a space can behave in a way redolant of quantum mechanics; additional degrees of freedom permit 'tunnelling' without recourse to…

Quantum Physics · Physics 2012-02-21 Ray J. Rivers

The complex-time formalism is developed in the framework of the path-integral formalism, to be used for analysis of the quantum tunneling phenomena. We show that subleading complex-time saddle-points do not account for the right WKB result.…

High Energy Physics - Theory · Physics 2011-07-19 Hideaki Aoyama , Toshiyuki Harano
‹ Prev 1 2 3 10 Next ›