共查询到20条相似文献,搜索用时 15 毫秒
1.
An Invitation to Quantum Game Theory 总被引:1,自引:0,他引:1
Recent development in quantum computation and quantum information theory allows to extend the scope of game theory for the quantum world. The paper presents the history, basic ideas, and recent development in quantum game theory. In this context, a new application of the Ising chain model is proposed. 相似文献
2.
Brandon Carter 《International Journal of Theoretical Physics》2004,43(3):721-730
The problem of interpreting quantum theory on a large (e.g. cosmological) scale has been commonly conceived as a search for objective reality in a framework that is fundamentally probabilistic. The Everett programme attempts to evade the issue by the reintroduction of determinism at the global level of a state vector of the universe. The present approach is based on the recognition that, like determinism, objective reality is an unrealistic objective. It is shown how an objective theory of an essentially subjective reality can be set up using an appropriately weighted probability measure on the relevant set of Hilbert subspaces. It is suggested that an entropy principle (superseding the weak anthropic principle) should be used to provide the weighting that is needed. The application of this ansatz to a toy gedanken example (involving Schroedinger's legendary cat) is described in an appendix. 相似文献
3.
A. Iqbal A.H. Toor 《理论物理通讯》2004,42(9)
In bimatrix games the Bishop-Cannings theorem of the classical evolutionary game theory does not permitpure evolutionarily stable strategies (ESSs) when a mixed ESS exists. We find the necessary form of two-qubit initialquantum states when a switch-over to a quantum version of the game also changes the evolutionary stability of a mixedsymmetric Nash equilibrium. 相似文献
4.
In this paper, making use of recent statistical physics techniques and models, we address the specific role of randomness in financial markets, both at the micro and the macro level. In particular, we review some recent results obtained about the effectiveness of random strategies of investment, compared with some of the most used trading strategies for forecasting the behaviour of real financial indexes. We also push forward our analysis by means of a self-organised criticality model, able to simulate financial avalanches in trading communities with different network topologies, where a Pareto-like power law behaviour of wealth spontaneously emerges. In this context, we present new findings and suggestions for policies based on the effects that random strategies can have in terms of reduction of dangerous financial extreme events, i.e. bubbles and crashes. 相似文献
5.
T. Kaizoji 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(1-2):123-127
In this paper, we quantitatively investigate the properties of a statistical ensemble of stock prices. We focus attention
on the relative price defined as X(t) = S(t)/S(0), where S(0), is the stock price for an onset time of the bubble. We selected
approximately 3200 stocks traded on the Japanese Stock Exchange, and formed a statistical ensemble of daily relative prices
for each trading day in the 3-year period from January 4, 1999 to December 28, 2001, corresponding to the period in which
internet Bubble formed and crashed in the Japanese stock market.
We found that the upper tail of the complementary cumulative distribution function of the ensemble of the relative prices
in the high value of the price is well described by a power-law distribution, P(S>x) ∼x-α , with an exponent that moves over time. Furthermore we found that as the power-law exponents α approached two, the bubble burst. It is reasonable to suppose that it indicates that internet bubble is about to burst. 相似文献
6.
This paper presents how a non-commutative version of the entropy extremalization principle allows to construct new quantum hydrodynamic models. Our starting point is the moment method, which consists in integrating the quantum Liouville equation with respect to momentum p against a given vector of monomials of p. Like in the classical case, the so-obtained moment system is not closed. Inspired from Levermore's procedure in the classical case,(26) we propose to close the moment system by a quantum (Wigner) distribution function which minimizes the entropy subject to the constraint that its moments are given. In contrast to the classical case, the quantum entropy is defined globally (and not locally) as the trace of an operator. Therefore, the relation between the moments and the Lagrange multipliers of the constrained entropy minimization problem becomes nonlocal and the resulting moment system involves nonlocal operators (instead of purely local ones in the classical case). In the present paper, we discuss some practical aspects and consequences of this nonlocal feature. 相似文献
7.
Quantum state targeting is a quantum game which results from combining traditional quantum state estimation with additional
classical information. We consider a particular version of the game and show how it can be played with maximally entangled
states. The optimal solution of the game is used to derive a Bell inequality for two entangled qutrits. We argue that the
nice properties of the inequality are direct consequences of the method of construction. 相似文献
8.
Over the last twenty years, quantum game theory has given us many ideas of how quantum games could be played. One of the most prominent ideas in the field is a model of quantum playing bimatrix games introduced by J. Eisert, M. Wilkens and M. Lewenstein. The scheme assumes that players’ strategies are unitary operations and the players act on the maximally entangled two-qubit state. The quantum nature of the scheme has been under discussion since the article by Eisert et al. came out. The aim of our paper was to identify some of non-classical features of the quantum scheme. 相似文献
9.
N. Sazuka 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(1-2):129-131
A non-trivial probability structure is evident in the binary data extracted from the up/down price movements of very high
frequency data such as tick-by-tick data for USD/JPY. In this paper, we analyze the Sony bank USD/JPY rates, ignoring the
small deviations from the market price. We then show there is a similar non-trivial probability structure in the Sony bank
rate, in spite of the Sony bank rate's having less frequent and larger deviations than tick-by-tick data. However, this probability
structure is not found in the data which has been sampled from tick-by-tick data at the same rate as the Sony bank rate. Therefore,
the method of generating the Sony bank rate from the market rate has the potential for practical use since the method retains
the probability structure as the sampling frequency decreases. 相似文献
10.
F. Petroni M. Serva 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,51(4):601-608
The present study shows how the information on `hidden' market variables effects optimal investment strategies. We take the
point of view of two investors, one who has access to the hidden variables and one who only knows the quotes of a given asset.
Following Kelly's theory on investment strategies, the Shannon information and the doubling investment rate are quantified
for both investors. Thanks to his privileged knowledge, the first investor can follow a better investment strategy. Nevertheless,
the second investor can extract some of the hidden information looking at the past history of the asset variable. Unfortunately,
due to the complexity of his strategy, this investor will have computational difficulties when he tries to apply it. He will
than follow a simplified strategy, based only on the average sign of the last l quotes of the asset. This results have been
tested with some Monte Carlo simulations. 相似文献
11.
I. Simonsen P. T.H. Ahlgren M. H. Jensen R. Donangelo K. Sneppen 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,57(2):153-158
The value of stocks, indices and other assets, are examples of stochastic processes with unpredictable dynamics. In this paper,
we
discuss asymmetries in short term price movements that can not be
associated with a long term positive trend. These empirical
asymmetries predict that stock index drops are more common on a
relatively short time scale than the corresponding raises. We
present several empirical examples of such asymmetries. Furthermore,
a simple model featuring occasional short periods of synchronized
dropping prices for all stocks constituting the index is introduced
with the aim of explaining these facts. The collective negative
price movements are imagined triggered by external factors in our
society, as well as internal to the economy, that create fear of the
future among investors. This is parameterized by a “fear factor”
defining the frequency of synchronized events. It is demonstrated
that such a simple fear factor model can reproduce several empirical
facts concerning index asymmetries. It is also pointed out that in
its simplest form, the model has certain shortcomings. 相似文献
12.
S. Alfarano T. Lux F. Wagner 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,55(2):183-187
The present paper expands on recent attempts at
estimating the parameters of simple interacting-agent models of
financial markets [S. Alfarano, T. Lux, F. Wagner, Computational Economics 26, 19 (2005); S. Alfarano, T. Lux, F. Wagner, in Funktionsf?higkeit und
Stabilit?t von Finanzm?rkten, edited by W. Franz, H. Ramser,
M. Stadler (Mohr Siebeck, Tübingen, 2005), pp. 241–254]. Here we
provide additional evidence by (i) investigating a large sample of
individual stocks from the Tokyo Stock Exchange, and (ii)
comparing results from the baseline noise trader/fundamentalist
model of [S. Alfarano, T. Lux, F. Wagner, Computational Economics 26, 19 (2005)] with those obtained from an even
simpler version with a preponderance of noise trader behaviour. As
it turns out, this somewhat more parsimonious “maximally skewed”
variant is often not rejected in favor of the more complex
version. We also find that all stocks are dominated by noise
trader behaviour irrespective of whether the data prefer the
skewed or the baseline version of our model. 相似文献
13.
S. Ciliberti M. Mézard 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,57(2):175-180
We use a replica approach to deal with portfolio optimization problems. A
given risk measure is minimized using empirical estimates of asset values
correlations. We study the phase transition which happens when the time
series is too short with respect to the size of the portfolio. We also study
the noise sensitivity of portfolio allocation when this transition is
approached. We consider explicitely the cases where the absolute deviation
and the conditional value-at-risk are chosen as a risk measure. We show how
the replica method can study a wide range of risk measures, and deal with
various types of time series correlations, including realistic ones with
volatility clustering. 相似文献
14.
Frank V. Kowalski 《Annalen der Physik》2023,535(1):2200287
An interferometer in which all of its components are treated as quantum bodies is examined with the standard interpretation and with a model in which its uncoupled spatially separated components act collectively. These models utilize superposition principles that differ when applied to systems composed of three or more bodies. Interferometric discrepancies between these models that involve frequency shifts and recoil are shown to be difficult to measure. More pronounced differences involve quantum correlated interference. The collective model provides a missing connection between quantum and semiclassical theories. Scattering from an entangled state, which cannot be divided into disjoint parts, is proposed to involve such collective recoil. Collective scattering offers a viable supplement to the standard model, thereby providing insight into constructing tests of the superposition principle in systems with three or more bodies. 相似文献
15.
The Principle Underlying Quantum Mechanics 总被引:1,自引:0,他引:1
The present article reports on the finding of the principle behind quantum mechanics. The principle, referred to as genuine fortuitousness, implies that the basic event, a click in a counter, comes without any cause and thus as a discontinuity in spacetime. From this principle, the formalism of quantum mechanics emerges with a radically new content, no longer dealing with things (atoms, particles, or fields) to be measured. Instead, quantum mechanics is recognized as the theory of distributions of uncaused clicks that form patterns laid down by spacetime symmetry and is thereby revealed as a subject of unexpected simplicity and beauty. The departure from usual quantum mechanics is strikingly borne out by the absence of Planck's constant from the theory. The elimination of indeterminate particles as cause for the clicks, which the principle of genuine fortuitousness implies, is analogous to the elimination of the ether implied by the principle of relativity. 相似文献
16.
A. P. Nawroth J. Peinke 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(1-2):147-151
A new approach is presented to describe the change in the statistics of the log return distribution of financial data as a
function of the timescale. To this purpose a measure is introduced, which quantifies the distance of a considered distribution
to a reference distribution. The existence of a small timescale regime is demonstrated, which exhibits different properties
compared to the normal timescale regime for timescales larger than one minute. This regime seems to be universal for individual
stocks. It is shown that the existence of this small timescale regime is not dependent on the special choice of the distance
measure or the reference distribution. These findings have important implications for risk analysis, in particular for the
probability of extreme events. 相似文献
17.
M. Bartolozzi 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,57(3):337-345
Avalanches, or Avalanche-like, events are often
observed in the dynamical behaviour of many complex systems which
span from solar flaring to the Earth's crust dynamics and from
traffic flows to financial markets. Self-organized criticality
(SOC) is one of the most popular theories able to explain this
intermittent charge/discharge behaviour. Despite a large amount of
theoretical work, empirical tests for SOC are still in their
infancy. In the present paper we address the common problem of
revealing SOC from a simple time series without having much
information about the underlying system. As a working example we
use a modified version of the multifractal random walk originally
proposed as a model for the stock market dynamics. The study
reveals, despite the lack of the typical ingredients of SOC, an
avalanche-like dynamics similar to that of many physical systems.
While, on one hand, the results confirm the relevance of cascade
models in representing turbulent-like phenomena, on the other,
they also raise the question about the current state of
reliability of SOC inference from time series analysis. 相似文献
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