The Einstein Equivalence Principle (EEP) can be probed with astrophysical sources emitting simultaneously different types of neutral particles, or particles with varying energies, by testing their time of flight through the same gravitational field. Here we use the time delays between correlated photons from cosmological transients to constrain the accuracy of the EEP. We take data from two gamma-ray bursts as an example, and use, as a lower limit to the theoretical time delays between different energies, delays arising from only the gravitational field of our own galaxy. We then show that the parameterized post-Newtonian parameter $\gamma$ is the same for photons over energy ranges between eV and MeV and between MeV and GeV to a part in $10^{-7}$, which is at least one order of magnitude better than previous limits. Combining this bound on the wavelength dependence of $\gamma$ with the absolute bound $|\gamma-1|<0.3\%$ from light-deflection measurements at optical (eV) wavelengths, we thus extend this absolute bound on $\gamma$ to GeV energies.

Cosmic Transients Test Einstein's Equivalence Principle out to GeV Energies

The Einstein Equivalence Principle (EEP) can be probed with astrophysical sources emitting simultaneously different types of neutral particles, or particles with varying energies, by testing their time of flight through the same gravitational field. Here we use the time delays between correlated photons from cosmological transients to constrain the accuracy of the EEP. We take data from two gamma-ray bursts as an example and, as a lower limit to the theoretical time delays between different energies, we use delays arising from only the gravitational field of our own galaxy. We then show that the parameterized post-Newtonian parameter gamma is the same for photons over energy ranges between eV and MeV and between MeV and GeV to a part in 10(-7), which is at least one order of magnitude better than previous limits. Combining this bound on the wavelength dependence of gamma with the absolute bound vertical bar gamma - 1 vertical bar < 0.3% from light-deflection measurements at optical (eV) wavelengths, we thus extend this absolute bound on gamma to GeV energies.

http://iopscience.iop.org/article/10.1088/0004-637X/810/2/121/pdf

COSMIC TRANSIENTS TEST EINSTEIN'S EQUIVALENCE PRINCIPLE OUT to GeV ENERGIES

To study short stochastic optical flares of different objects (GRBs, SNs, etc.) of
unknown localizations as well as NEOs it is necessary to monitor large regions
of sky with high-time resolution. We developed a system consisting of widefield
camera with field of view of 400–600 sq.deg. which uses TV-CCD with
0.13 s temporal resolution to record and classify optical transients, and a fast
robotic telescope aimed to perform their spectroscopic and photometric investigation
just after detection. Such two-telescope complex, combining wide-field
camera TORTORA and robotic telescope REM, operated from May 2006 at
La Silla ESO observatory. Some results of its operation, including first high
time resolution study of optical transient accompanying GRB and discovery
of its fine time structure, are presented. Also, prospects for improving the
efficiency of such observations are given, and a project of a next generation
wide field monitoring system, the MegaTORTORA, is described.

/pdf/from-tortora-to-megatortora-results-and-prospects-of-search-fzva47c9ld.pdf

From TORTORA to MegaTORTORA—Results and Prospects of Search for Fast Optical Transients

In order to detect and investigate short stochastic optical flares from a number of variable astrophysical objects (GRBs, SNe, flare stars, CVs, X-Ray binaries) of unknown localizations as well as near-earth objects (NEOs), both
natural and artificial, it is necessary to perform the systematic monitoring of large regions of the sky with high temporal resolution. Here we discuss the criteria for a system that is able to perform such a task and describe two cameras we created for wide-field monitoring with high temporal resolution—FAVOR and TORTORA. Also, we describe basic principles of real-time data processing for the high frame rates needed to achieve subsecond temporal resolution on a typical hardware.

/pdf/wide-and-fast-monitoring-the-sky-in-subsecond-domain-with-681t5ty88v.pdf

Wide and Fast: Monitoring the Sky in Subsecond Domain with the FAVOR and TORTORA Cameras

Construction of robotic observatories has developed into an important and thriving field of astronomy. Their large field of view combined with the capability to be pointed at any direction makes robotic astronomical systems indispensable for tasks involving searches for transients like GRB, supernovae explosions, novae, and so forth, where both the time and direction of the search are impossible to predict. This paper describes prompt GRB observations made with MASTER-VWF wide-field cameras and the methods of image analysis and classification of transients used for real-time data processing. During seven months of operation six synchronous observations of gamma-ray bursts have been made using MASTER VWF facilities deployed in Kislovodsk and Irkutsk. In all cases high upper limits have been obtained.

/pdf/transient-detections-and-other-real-time-data-processing-17uzms8tho.pdf

Transient Detections and Other Real-Time Data Processing from MASTER-VWF Wide-Field Cameras

A new astronomical complex intended to study fast optical transients is presented. It is placed at the La Silla observatory in Chile. Here we present first results of its operation.

TORTOREM: Two-telescope complex for detection and investigation of optical transients

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

C. Bartdlini

Author Tools

Chat about Author

Papers

TORTOREM: Two-telescope complex for detection and investigation of optical transients