Neutrino Oscillations from String Theory

We derive the character of neutrino oscillations that results from a model of equivalence principle violation suggested recently by Damour and Polyakov as a plausible consequence of string theory. In this model neutrino oscillations will take place through interaction with a long range scalar field of gravitational origin even if the neutrinos are degenerate in mass. The energy dependence of the oscillation length is identical to that in the conventional mass mixing mechanism. This possibility further highlghts the independence of and need for more exacting direct neutrino mass measurements together with a next generation of neutrinoless double beta decay experiments.Comment: 7 pages LaTE

Neutrino Oscillations from Strings and Other Funny Things

I will discuss three related unconventional ways to generate neutrino oscillations (1)Equivalence principle violation by the string dilaton field (i2)Violation of Lorentz Invariance and (3) Equivalence principle violation through a non-universal tensor neutrino-gravity coupling. These unorthodox neutrino oscillation mechanisms are shown to be viable at the level of our present experimental knowledge and demonstrate that neutrino oscillations can probe very profound questions

Comments on Neutrino Tests of Special Relativity

We point out that the assumption of Lorentz noninvariance examined recently by Coleman and Glashow leads to neutrino flavor oscillations which are phenomenologically equivalent to those obtained by assuming the neutrinos violate the principle of equivalence. We then comment on the limits on Lorentz noninvariance which can be derived from solar, atmospheric, and accelerator neutrino experiments.Comment: 5 pages, Revte

When Can Limited Randomness Be Used in Repeated Games?

The central result of classical game theory states that every finite normal form game has a Nash equilibrium, provided that players are allowed to use randomized (mixed) strategies. However, in practice, humans are known to be bad at generating random-like sequences, and true random bits may be unavailable. Even if the players have access to enough random bits for a single instance of the game their randomness might be insufficient if the game is played many times. In this work, we ask whether randomness is necessary for equilibria to exist in finitely repeated games. We show that for a large class of games containing arbitrary two-player zero-sum games, approximate Nash equilibria of the $n$-stage repeated version of the game exist if and only if both players have $\Omega(n)$ random bits. In contrast, we show that there exists a class of games for which no equilibrium exists in pure strategies, yet the $n$-stage repeated version of the game has an exact Nash equilibrium in which each player uses only a constant number of random bits. When the players are assumed to be computationally bounded, if cryptographic pseudorandom generators (or, equivalently, one-way functions) exist, then the players can base their strategies on "random-like" sequences derived from only a small number of truly random bits. We show that, in contrast, in repeated two-player zero-sum games, if pseudorandom generators \emph{do not} exist, then $\Omega(n)$ random bits remain necessary for equilibria to exist

Neutrino oscillations from the splitting of Fermi points

As was shown previously, oscillations of massless neutrinos may be due to the splitting of multiply degenerate Fermi points. In this Letter, we give the details and propose a three-flavor model of Fermi point splittings and neutrino mixings with only two free parameters. The model may explain recent experimental results from the K2K and KamLAND collaborations. There is also rough agreement with the data on atmospheric neutrinos (SuperK) and solar neutrinos (SNO), but further analysis is required. Most importantly, the Ansatz allows for relatively strong T-violating (CP-nonconserving) effects in the neutrino sector.Comment: 6 pages with jetplFRK.cls, v4: published versio

Solar Neutrinos and the Violation of Equivalence Principle

In this Brief Report, a non-standard solution to the solar neutrino problem is revisited. This solution assumes that neutrino flavors could have different couplings to gravity, hence, the equivalence principle is violated in this mechanism. The gravity induced mixing has the potential of accounting for the current solar neutrino data from several experiments even for massless neutrinos. We fit this solution to the total rate of neutrino events in the SuperKamiokande detector together with the total rate from other detectors and also with the most recent results of the SuperKamiokande results for the recoil-electron spectrum.Comment: 6 pages, 4 figures, submitted to Phys.Rev.

An Investigation of Equivalence Principle Violations Using Solar Neutrino Oscillations in a Constant Gravitational Potential

Neutrino oscillations induced by a flavor-dependent violation of the Einstein Equivalence Principle (VEP) have been recently considered as a suitable explanation of the solar electron-neutrino deficiency. Unlike the MSW oscillation mechanism, the VEP mechanism is dependent on a coupling to the local background gravitational potential $\Phi$. We investigate the differences which arise by considering three-flavor VEP neutrinos oscillating against fixed background potentials, and against the radially-dependent solar potential. This can help determine the sensitivity of the gravitationally-induced oscillations to both constancy and size (order of magnitude) of $\Phi$. In particular, we consider the potential of the local superculster, $|\Phi|=3\times 10^{-5}$, in light of recent work suggesting that the varying solar potential has no effect on the oscillations. The possibility for arbitrarily large background potentials in different cosmologies is discussed, and the effects of one such potential ($\Phi = 10^{-3}$) are considered.Comment: 12pp, LaTeX; 12 figures (bitmapped postscript); Submitted to Phys Rev