# Are we 4D hologram?

June 20, 2009 1 Comment

Are we hologram? The one thing which can give answer is holographic theory. A special version of holographic theory known as adS/CFT correspondance, is saying this. The adS/CFT correspondece is a type of duality, which states that two apparently distinct physical theories are actually equivalent. On one side of this duality is the physics of gravity in space time known as anti-de Sitter space(adS). This five dimensional adS has a boundry which is four dimensional, and in a certain limit looks like a flat space time. The adS correspondece states that physics of gravity in five dimensional adS is equivalent to a certain supersymmetric Yang Mills theory which is defined on the boundsy of adS. This Yang Mills theory is thus a hologram of the physics which is actually happening in five dimensions. The Yang Mills theory has gauge group SU(N), where N is very large and it is said to be supersymmetric because it has symmetry which allows you to exchange bosons and fermions. It can tell something more about QCD which is a gauge theory with gauge group SU(3). QCD describes interaction between quarks. However, QCD has less symmetry than the theory that defined on the boundry of adS. As you go far away from this 4D boundry of adS you move in fifth dimension in a similar way if someone moves away from three dimensional (one time dimension) hologram , it will actually moving in a fourth space dimension. And that’s how we are 4 dimensional hologram.

There’s another guy out there going the opposite way with his theory, trying to find out if we’re actually 2 dimensional objects projected into 3D, like a normal hologram.