According to wikipedia:
The zero-energy universe hypothesis states that the total amount of energy in the universe is exactly zero. When the energy of the universe is considered from a pseudo-tensor point of view, zero values are obtained in the resulting calculations.[1] The amount of positive energy in form of matter is exactly canceled out by the negative energy in form of gravity
However, if we introduce a point symmetric multiverse, with a raspberry or blackberry shape, then we may say that the positive energy in a material berry -like our universe- is canceled by the negative energy inside the Charge, Parity and Time symmetric anti material opposite berry shaped-universe.
Time is there in fact not running backwards their clocks are rotating in the other direction! Electrons are positive charged and left handed systems are right handed, directly entangled down to the the quantum level.
see for zero energy multiverse in raspberry shape:
A Grand Design for an entangled 12 fold symmetric multiverse in raspberry shape.
The Raspberry or Blackberry multiverse.
Behind it all is surely an idea so simple, so beautiful, that when we grasp it - in a decade, a century, or a millennium - we will all say to each other, how could it have been otherwise? How could we have been so stupid for so long? - John Archibald Wheeler
The Q-FFF Rigid String Theory says: (1) There is only one CONSTRUCTIVE Topological and Resilient TRANSFORMING STRING (Axion/vacuum Dark Energy building block ), forming direct after the Black Hole Splitting Big Bang. so called Travelling TADPOLE Black Hole based Filaments, expanding the Cosmic Lyman Alpha Structure. (2) A Raspberry Entangled 12x Mirror Copy Multiverse is Postulated as base for uncertainty (ER=EPR) and Libet's FREE VETO WILL . SO We live inside an exploded BH