#### Alladi Ramakrishnan Hall

#### The Turbulent Vacuum

#### A P Balachandran

##### CMI, Chennai

*The following work is jointly done with M.Asorey, F.Lizzi and G.Marmo.*

The vacuum state in relativistic quantum field theory is often pictured as devoid of striking properties, as vacuous. But instead the following are true :

1) Atoms or measuring apparatus inserted at space-like distances in vacuum should exhibit no correlations in the above image of the vacuum. But instead if they have localised states with orthogonal wave functions, and atom 1 is in ground state and 2 in an excited state at a space-like distance, either 1 will *never *be affected by 2 via photon emission (which is absurd) or it will be *instantaneously* affected violating causality.

2) Fields in a finite region, no matter how small, acting on the vacuum can produce *any* state in the Hilbert space.

3) Invariance of the vacuum is invariance of the world. (Coleman).

4)There are * no *localised detectors ! ( Implications for a causal quantum information theory ?)

After discussions of the above, we apply them to the Rindler wedge. There we show that photon *cannot* be confined to the wedge : there is information leakage out of the wedge (but no unitarity violation). This happens because in qed , infrared effects break Lorentz invariance . The above result has potential applications to black hole information paradox.

Done