جهت دسترسی به کاربرگه ی زیر، از این لینک استفاده کنید. http://dl.pgu.ac.ir/handle/Hannan/84382
Title: Correlation between opposite-helicity gravitons: Imprints on gravity-wave and microwave backgrounds
Keywords: Science & Technology;Physical Sciences;Astronomy & Astrophysics;Physics, Particles & Fields;Physics;POLARIZATION;FLUCTUATIONS;gr-qc;gr-qc;astro-ph.CO;Nuclear & Particles Physics;0201 Astronomical And Space Sciences;0202 Atomic, Molecular, Nuclear, Particle And Plasma Physics;0206 Quantum Physics
Issue Date: 30-Jan-2017
10-Jan-2017
Publisher: American Physical Society
Description: We examine some of the roots of parity violation for gravitons and uncover a closely related new effect: correlations between right and left handed gravitons. Such correlators have spin 4 if they involve gravitons moving along the same direction, and spin zero for gravitons moving with opposite directions. In the first case, the most immediate implication would be a degree of linear polarization for the tensor vacuum fluctuations, which could be seen by gravity wave detectors sensitive enough to probe the primordial background, its degree of polarization and anisotropies. Looking at the anisotropy of the gravity waves linear polarization we identify the parity respecting and violating components of the effect. The imprint on the CMB temperature and polarization would be more elusive, since it averages to zero in the two-point functions, appearing only in their cosmic variance or in fourth order correlators. In contrast, spin zero correlations would have an effect on the two point function of the CMB temperature and polarization, enhancing the $BB$ component if they were anti-correlations. Such correlations represent an amplitude for the production of standing waves, as first envisaged by Grishchuk, and could also leave an interesting signature for gravity wave detectors.
URI: https://dx.doi.org/10.1103/PhysRevD.95.023520
Other Identifiers: http://arxiv.org/abs/1610.05702v1
1550-7998
http://hdl.handle.net/10044/1/44094
ID#47633
Type Of Material: Other
Appears in Collections:Physics

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