ترغب بنشر مسار تعليمي؟ اضغط هنا

Clocks and Relationalism in the Thermal Time Hypothesis

174   0   0.0 ( 0 )
 نشر من قبل Nicolas Menicucci
 تاريخ النشر 2011
  مجال البحث فيزياء
والبحث باللغة English




اسأل ChatGPT حول البحث

The Thermal Time Hypotheis (TTH) has been proposed as a general method for identifying a time variable from within background-free theories which do not come equipped with a pre-defined clock variable. Here, we explore some implications of the TTH in an entirely relational context by constructing a protocol for the creation of thermal clocks from components of a large but finite quantum mechanical system. The protocol applies locally, in the sense that we do not attempt to construct a single clock describing the evolution of the entire system, but instead we construct clocks which describe the evolution of each subsystem of interest. We find that a consistency condition required for the evolution of our clocks is operationally equivalent to the general relativistic Tolman-Ehrenfest relation for thermal equilibrium in a static gravitational field but without the assumption of gravity or a metric field of any kind.



قيم البحث

اقرأ أيضاً

The performance of optical clocks has strongly progressed in recent years, and accuracies and instabilities of 1 part in 10^18 are expected in the near future. The operation of optical clocks in space provides new scientific and technological opportu nities. In particular, an earth-orbiting satellite containing an ensemble of optical clocks would allow a precision measurement of the gravitational redshift, navigation with improved precision, mapping of the earths gravitational potential by relativistic geodesy, and comparisons between ground clocks.
We discuss the theoretical analysis and interpretation of space-time separated clock experiments in the context of a space-time varying scalar field that is non-universally coupled to the standard model fields. If massive, such a field is a candidate for dark matter and could be detected in laboratory experiments. We show that space-time separated experiments have the potential to probe a fundamentally different parameter space from more common co-located experiments, allowing decorrelation of previously necessarily correlated parameters. Finally, we describe such a space-time separated clock experiment currently running at the Paris Observatory, and present some preliminary results as a proof of principle.
377 - Travis Garrett 2011
The discovery of a small cosmological constant has stimulated interest in the measure problem. One should expect to be a typical observer, but defining such a thing is difficult in the vastness of an eternally inflating universe. We propose that a cr ucial prerequisite is understanding why one should exist as an observer at all. We assume that the Physical Church Turing Thesis is correct and therefore all observers (and everything else that exists) can be described as different types of information. We then argue that the observers collectively form the largest class of information (where, in analogy with the Faddeev Popov procedure, we only count over gauge invariant forms of information). The statistical predominance of the observers is due to their ability to selectively absorb other forms of information from many different sources. In particular, it is the combinatorics that arise from this selection process which leads us to equate the observer class $mathcal{O}$ with the nontrivial power set $hat{mathcal{P}}(mathcal{U})$ of the set of all information $mathcal{U}$. Observers themselves are thus the typical form of information. If correct, this proposal simplifies the measure problem, and leads to dramatic long term predictions.
The Riemann Hypothesis states that the Riemann zeta function $zeta(z)$ admits a set of non-trivial zeros that are complex numbers supposed to have real part $1/2$. Their distribution on the complex plane is thought to be the key to determine the numb er of prime numbers before a given number. We analyze two approaches. In the first approach, suggested by Hilbert and Polya, one has to find a suitable Hermitian or unitary operator whose eigenvalues distribute like the zeros of $zeta(z)$. In the other approach one instead compares the distribution of the zeta zeros and the poles of the scattering matrix $S$ of a system. We apply the infinite-components Majorana equation in a Rindler spacetime to both methods and then focus on the $S$-matrix approach describing the bosonic open string for tachyonic states. In this way we can explain the still unclear point for which the poles and zeros of the $S$-matrix overlaps the zeros of $zeta(z)$ and exist always in pairs and related via complex conjugation. This occurs because of the relationship between the angular momentum and energy/mass eigenvalues of Majorana states and from the analysis of the dynamics of the poles of $S$. As shown in the literature, if this occurs, then the Riemann Hypothesis can in principle be satisfied.
For the purpose of searching for Lorentz-invariance violation in the minimal Standard-Model Extension, we perfom a reanalysis of data obtained from the $^{133}text{Cs}$ fountain clock operating at SYRTE. The previous study led to new limits on eight components of the $tilde{c}_{mu u}$ tensor, which quantifies the anisotropy of the proton kinetic energy. We recently derived an advanced model for the frequency shift of hyperfine Zeeman transition due to Lorentz violation and became able to constrain the ninth component, the isotropic coefficient $tilde{c}_{TT}$, which is the least well-constrained coefficient of $tilde{c}_{mu u}$. This model is based on a second-order boost Lorentz transformation from the laboratory frame to the Sun-centered frame, and it gives rise to an improvement of five orders of magnitude on $tilde{c}_{TT}$ compared to the state of the art.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا