Cosmic Accelerators: An Introduction

Kanbach, G.

doi:10.1063/1.2141826

Cited by 8 publications

(11 citation statements)

References 1 publication

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“…The neutron star itself emits pulsed radiation at its rotation fre-quency of 30 Hz. In the optical band these pulses are superimposed on a fainter steady component with a linear polarization degree of 30% and direction precisely aligned with that of the rotation axis [108]. The direction of polarization measured by INTEGRAL-SPI in the γ-rays is θ obs = 123 • ± 11 • (1σ error) from the North, thus also closely aligned with the jet direction and remarkably consistent with the optical observations.…”

Section: Photon Polarizationsupporting

confidence: 82%

Lorentz Breaking Effective Field Theory Models for Matter and Gravity: Theory and Observational Constraints

Liberati

Mattingly

2015

Gravity: Where Do We Stand?

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A number of different approaches to quantum gravity are at least partly phenomenologically characterized by their treatment of Lorentz symmetry, in particular whether the symmetry is exact or modified/broken at the smallest scales. For example, string theory generally preserves Lorentz symmetry while analog gravity and Lifshitz models break it at microscopic scales. In models with broken Lorentz symmetry there are a vast number of constraints on departures from Lorentz invariance that can be established with low energy experiments by employing the techniques of effective field theory in both the matter and gravitational sectors. We shall review here the low energy effective field theory approach to Lorentz breaking in these sectors and present various constraints provided by available observations. 122. A.V. Kostelecky, J.D. Tasson, Phys.Rev. D83, 016013 (2011).

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Section: Photon Polarizationsupporting

confidence: 82%

Lorentz Breaking Effective Field Theory Models for Matter and Gravity: Theory and Observational Constraints

Liberati

Mattingly

2015

Gravity: Where Do We Stand?

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“…The neutron star itself emits pulsed radiation at its rotation frequency of 30 Hz. In the optical band these pulses are superimposed on a fainter steady component with a linear polarization degree of 30% and direction precisely aligned with that of the rotation axis [151]. The direction of polarization measured by INTEGRAL-SPI in the γ-rays is θ obs = 123 • ± 11 • (1σ error) from the North, thus also closely aligned with the jet direction and remarkably consistent with the optical observations.…”

Section: Birefringence Constraintsupporting

confidence: 82%

Lorentz Breaking Effective Field Theory and Observational Tests

Liberati

2013

Lecture Notes in Physics

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Analogue models of gravity have provided an experimentally realizable test field for our ideas on quantum field theory in curved spacetimes but they have also inspired the investigation of possible departures from exact Lorentz invariance at microscopic scales. In this role they have joined, and sometime anticipated, several quantum gravity models characterized by Lorentz breaking phenomenology. A crucial difference between these speculations and other ones associated to quantum gravity scenarios, is the possibility to carry out observational and experimental tests which have nowadays led to a broad range of constraints on departures from Lorentz invariance. We shall review here the effective field theory approach to Lorentz breaking in the matter sector, present the constraints provided by the available observations and finally discuss the implications of the persisting uncertainty on the composition of the ultra high energy cosmic rays for the constraints on the higher order, analogue gravity inspired, Lorentz violations.

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“…The expected properties of polarization in a two-pole caustic geometry have been investigated by . They found that the position angle and polarization degree as a function of phase produce a reasonable match to the optical polarization of the Crab pulsar (Kanbach et al 2005). Since the radiation modeled in this paper includes emission on interior field lines as well as in the slot gap, we expect that the polarization properties could be somewhat different and perhaps also energy dependent.…”

Section: Discussionmentioning

confidence: 70%

High‐Altitude Emission from Pulsar Slot Gaps: The Crab Pulsar

Harding¹,

Stern²,

Dyks³

et al. 2008

ApJ

186

217

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We present results of a 3D model of optical to γ-ray emission from the slot gap accelerator of a rotation-powered pulsar. Primary electrons accelerating to high-altitudes in the unscreened electric field of the slot gap reach radiationreaction limited Lorentz factors of ∼ 2 × 10 7 , while electron-positron pairs from lower-altitude cascades flow along field lines interior to the slot gap. The curvature, synchrotron and inverse Compton radiation of both primary electrons and pairs produce a broad spectrum of emission from infra-red to GeV energies. Both primaries and pairs undergo cyclotron resonant absorption of radio photons, allowing them to maintain significant pitch angles. Synchrotron radiation from pairs with a power-law energy spectrum from γ = 10 2 − 10 5 , dominate the spectrum up to ∼ 10 MeV. Synchrotron and curvature radiation of primaries dominates from 10 MeV up to a few GeV. We examine the energy-dependent pulse profiles and phase-resolved spectra for parameters of the Crab pulsar as a function of magnetic inclination α and viewing angle ζ, comparing to broad-band data. In most cases, the pulse profiles are dominated by caustics on trailing field lines. We also explore the relation of the high-energy and the radio profiles, as well as the possibility of caustic formation in the radio cone emission. We find that the Crab pulsar profiles and spectrum can be reasonably well reproduced by a model with α = 45 • and ζ ∼ 100 • or 80 • . This model predicts that the slot gap emission below 200 MeV will exhibit correlations in time and phase with the radio emission.

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Cosmic Accelerators: An Introduction

Cited by 8 publications

References 1 publication

Lorentz Breaking Effective Field Theory Models for Matter and Gravity: Theory and Observational Constraints

Lorentz Breaking Effective Field Theory Models for Matter and Gravity: Theory and Observational Constraints

Lorentz Breaking Effective Field Theory and Observational Tests

High‐Altitude Emission from Pulsar Slot Gaps: The Crab Pulsar

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