I have some questions regarding the temperature of empty space in a de Sitter universe or to say it better - the Hawking radiation emmited from the cosmological horizon: 1) Do particles that make up the radiation get produced by the empty space inside the patch (the Bunch Davies vacuum) or by the horizon which then 'sends them' into the interior? When it is said that the observer would detect a temperature, would he detect the temperature of the empty space or the temperature of the radiation emmited by the horizon which takes time to travel to the observer? 2) I watched a video from prof Lenny Susskind in which he talks about this situation with Hawking radiation and he says that most of the particles would be concentrated near the horizon. How would the temperature of empty space then be constant in any region since some would contain more particles than others? Furthermore, if there is another observer located differently, he would have a different horizon and he would describe the location of the 'many particles' of the first observer as a region with less particles, since his density would be greater near his own horizon. What is wrong with this argument? 3) Sean Carroll has made an argument that the temperature of de Sitter isn't real if nobody is measuring it, and that fluctuations can only arise when matter is present? Did he mean that fluctuations arise in normal matter in radiation before it redshifts away or that the fluctuations don't arise because the matter that redshifts away acts like a measuring device on the vacuum which is the thing that really produces particles? 4) If the horizon produces particles that become real like in the black hole case, what happens to the second pair which is left behind the horizon like falling into a black hole? And how can an observer in the center of the patch measure the creation of the particles, since by this logic they were created way before they came to the observer? As you can see I am very confused by this topic and I hope that it is not too nonsensical for some good answers. Thanks in advance.