scholarly journals CMB Temperature Polarization Correlation and Primordial Gravitational Waves: WMAP5

2009 ◽  
Vol 2009 ◽  
pp. 1-5
Author(s):  
N. J. Miller ◽  
B. G. Keating ◽  
A. G. Polnarev
Keyword(s):  
Power Spectrum ◽  
Gravitational Waves ◽  
Cross Correlation ◽  
Statistical Tests ◽  
Density Perturbation ◽  
Wiener Filters ◽  
Primordial Gravitational Waves ◽  
Temperature Polarization ◽  
Source Of Information ◽  
Cmb Temperature

we continue our study of the CMB temperature polarization (TE) cross-correlation as a source of information about primordial gravitational waves (PGWs). In a previous paper, we considered two methods for detecting PGWs using the TE cross-correlation. The first method is the zero multipole method, where we find the multipole,ℓ0, where the TE cross-correlation power spectrum,CℓTE, first changes sign. The second method Wiener filters the CMB TE data to remove the density perturbation contribution to the TE power spectrum. We then use statistical tests to determine if there is a detection of negative residual TE correlation and hence a detection of primordial gravitational waves, the only source of negative TE correlation at these superhorizon scales. In this paper, we will apply these tests to the WMAP 5-year data. We find that the TE power spectrum consistent withr< 2.0 at 95% confidence with no additional assumptions about the PGWs. If we assume that the PGWs are generated by inflation, then we getr< 1.0 at 95% confidence.

scholarly journals Probing primordial gravitational waves: Ali CMB Polarization Telescope

2018 ◽  
Vol 6 (1) ◽  
pp. 145-154 ◽  
Author(s):  
Hong Li ◽  
Si-Yu Li ◽  
Yang Liu ◽  
Yong-Ping Li ◽  
Yifu Cai ◽  
...  
Keyword(s):  
Gravitational Waves ◽  
High Energy Physics ◽  
Transition Edge Sensor ◽  
High Energy ◽  
Cpt Symmetry ◽  
Joint Project ◽  
Current Limit ◽  
Scientific Goal ◽  
Primordial Gravitational Waves ◽  
Cmb Polarization

Abstract In this paper, we will give a general introduction to the Ali CMB Polarization Telescope (AliCPT) project, which is a Sino–US joint project led by the Institute of High Energy Physics and involves many different institutes in China. It is the first ground-based Cosmic Microwave Background (CMB) polarization experiment in China and an integral part of China's Gravitational-wave Program. The main scientific goal of the AliCPT project is to probe the primordial gravitational waves (PGWs) originating from the very early Universe. The AliCPT project includes two stages. The first stage, referred to as AliCPT-1, is to build a telescope in the Ali region of Tibet at an altitude of 5250 meters. Once completed, it will be the highest ground-based CMB observatory in the world and will open a new window for probing PGWs in the northern hemisphere. The AliCPT-1 telescope is designed to have about 7000 transition-edge sensor detectors at 95 GHz and 150 GHz. The second stage is to have a more sensitive telescope (AliCPT-2) with more than 20 000 detectors. Our simulations show that AliCPT will improve the current constraint on the tensor-to-scalar ratio r by one order of magnitude with three years' observation. Besides the PGWs, AliCPT will also enable a precise measurement of the CMB rotation angle and provide a precise test of the CPT symmetry. We show that three years' observation will improve the current limit by two orders of magnitude.

scholarly journals TRACE OF PHASE-SPACE NONCOMMUTATIVITY IN RESPONSE OF A FREE PARTICLE TO LINEARIZED GRAVITATIONAL WAVES

2013 ◽  
Vol 28 (35) ◽  
pp. 1350161 ◽  
Author(s):  
SUNANDAN GANGOPADHYAY ◽  
ANIRBAN SAHA ◽  
SWARUP SAHA
Keyword(s):  
Phase Space ◽  
Gravitational Waves ◽  
Cross Correlation ◽  
Free Particle ◽  
Momentum Scale ◽  
Specific Frequency ◽  
Global Nature ◽  
Space Noncommutativity ◽  
Correlation Procedure ◽  
Noncommutative Parameter

Interaction of linearized gravitational waves with a otherwise free particle has been studied quantum mechanically in a noncommutative (NC) phase-space to examine whether the particle's response to the gravitational wave gets modified due to spatial and/or momentum noncommutativity. The result shows that momentum noncommutativity introduces a oscillatory noise with a specific frequency determined by the fundamental momentum scale and particle mass. Because of the global nature of the phase-space noncommutativity such noise will have similar characteristics for all detector sites and thus will stand out in a data cross-correlation procedure. If detected, this noise will provide evidence of momentum noncommutativity and also an estimation of the relevant noncommutative parameter.

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