The researchers of European Space Agency’s Planck space observatory tested a series of holographic models against observations of the very early universe. This model depends on the theory of quantum gravity, cosmic inflation, etc.

1. The Holographic Universe
Name of the Contributor: Jayita Dan
Department: Physics
Date of submission: 2nd
January’19
No. of words: 415
Brainware University
https://www.brainwareuniversity.ac.in/
Summary:
The researchers of European Space Agency’s Planck space observatory tested a series of holographic
models against observations of the very early universe. This model depends on the theory of quantum
gravity, cosmic inflation, etc.
Key Word:
• Quantum gravity
• Gravitational horizon
• Big Bang theory
• Black hole
• Event horizon
Contents:
"Imagine that everything you see, feel and hear in three dimensions and your perception of time, in fact
emanates from a flat two-dimensional field,” says Professor Kostas Skenderis, director of STAG at the
University of Southampton.
The holographic universe is a model based on a principle of string theories and a quantum gravity that states
a volume of space(the universe) can be thought of as encoded on a 2D surface bounded by a light-like
boundary like a gravitational horizon.
The irregularities in the cosmic microwaves give significant evidence to support a holographic explanation of
the universe. Theoretical physicists also astrophysicists explain of these irregularities using the theory of
cosmic inflation and the ‘afterglow’ of the Big Bang theory. They believe that our universe is like a big and
complex hologram where a three-dimensional image is encoded in a two-dimensional surface. The basic
principle is similar to the ordinary hologram. The recorded photograph is known as hologram. The principle of
recording of a hologram includes superposition of the scattered wave from the object and another coherent
wave known as reference wave of the same wavelength as scattered wave.
All the informations contained within a region of space are reconstructed from the information on the surface.
This means that the volume of space can be represented as a hologram of the two dimensional surfaces.
Rather it can be thought of as like watching a 3D cinema. We see the pictures(3D) having height, width and
depth in a flat 2D screen. The difference is that we can touch the objects in 3D universe, and the projection is
real from our point of view.
The holographic principle extends the idea of black holes to cosmology. For example, we cannot observe
anything within the interior because the gravity near a black hole is too high and that is why light cannot
escape. The black hole has a surface known as the event horizon, and we could observe everything outside
of that surface. So we can understand the interior of a black hole from information near the event horizon.
In recent decades, the advances of scientific equipments have allowed scientists to find that some of the
simplest quantum field theories could explain nearly all cosmological observations of the early universe.
According to Professor Skenderis holography is a great upsurge in the way of thinking of early universe. The
further understanding of the early universe is possible by this study. It will open the door to explain how
space and time emerged.

2. References:
1. Niayesh Afshordi, Claudio Corianò, Luigi Delle Rose, Elizabeth Gould, Kostas Skenderis. From Planck
Data to Planck Era: Observational Tests of Holographic Cosmology. Physical Review Letters, 2017; 118 (4)
DOI: 10.1103/PhysRevLett.118.041301
2. Universe-is-a-hologram.jpg