In order to enable an iCal export link, your account needs to have an API key created. This key enables other applications to access data from within Indico even when you are neither using nor logged into the Indico system yourself with the link provided. Once created, you can manage your key at any time by going to 'My Profile' and looking under the tab entitled 'HTTP API'. Further information about HTTP API keys can be found in the Indico documentation.
Additionally to having an API key associated with your account, exporting private event information requires the usage of a persistent signature. This enables API URLs which do not expire after a few minutes so while the setting is active, anyone in possession of the link provided can access the information. Due to this, it is extremely important that you keep these links private and for your use only. If you think someone else may have acquired access to a link using this key in the future, you must immediately create a new key pair on the 'My Profile' page under the 'HTTP API' and update the iCalendar links afterwards.
Permanent link for public information only:
Permanent link for all public and protected information:
Propagation of gamma-rays over intergalactic distances: A Probe for cosmology and new physics
(Oscar Klein Center)
FA 32 ()
Gamma rays with energies above tens of GeV originating from
extragalactic sources undergo pair production with photons of the extragalactic backgroundlight (EBL),
leading to an attenuation of the primary gamma-ray flux.
The EBL stretches from ultra-violett to far infrared wavelengths and encodes
the emitted starlight and starlight absorbed and re-emitted by dust in galaxies
integrated over the entire history of the universe.
The exact level of the EBL photon density remains unknown as direct observations
are impeded due to strong foreground contaminations.
Moreover, evidence exists that the gamma-ray opacity may be lower than expected from EBL models.
This tension can be mitigated if photons oscillate into hypothetical
The observation of gamma-rays with the larger area telescope
on board the Fermi satellite and with imaging air Cherenkov telescopes
offers an independent tool study to the EBL and to probe physics beyond the Standard Model.
Recent measurements and model constraints derived from gamma-ray data will be reviewed
and an outlook for studies the future Cherenkov telescope array is presented.