TY - JOUR

T1 - Relic topological defects from brane annihilation simulated in superfluid He-3.

AU - Bradley, D. Ian

AU - Fisher, Shaun N.

AU - Guénault, A.M.

AU - Haley, Richard P.

AU - Kopu, Juha

AU - Martin, Hazel

AU - Pickett, George R.

AU - Roberts, John Edward

AU - Tsepelin, Viktor

PY - 2008/1

Y1 - 2008/1

N2 - Although it is widely accepted that to resolve the 'horizon' problem the early Universe must have undergone a sudden expansion (cosmic inflation), what mechanism drove this process is less clear. In the braneworld scenario, it is suggested that inflationary epochs may have been initiated and terminated by brane collisions and annihilations. Branes are objects of lower dimensionality embedded in a higher-dimensional matrix. For example, we may live on a three-dimensional brane embedded in a four-dimensional matrix. However, such structures are so far removed from everyday reality that bringing physical insight to bear is difficult. Here we report laboratory experiments where we simulate brane annihilation using the closest brane analogue to which we have access, the coherent phase boundary between the two phases of superfluid He-3. When two branes collide or annihilate, topological defects may be created, whose influence may still be detectable today. By creating a brane-antibrane pair in superfluid He-3 and subsequently annihilating it, we can detect that defects are indeed created in the superfluid texture (the superfluid analogue of spacetime), thus confirming that the concept of defect formation after brane annihilation in the early Universe can be reproduced in analogous systems in the laboratory.

AB - Although it is widely accepted that to resolve the 'horizon' problem the early Universe must have undergone a sudden expansion (cosmic inflation), what mechanism drove this process is less clear. In the braneworld scenario, it is suggested that inflationary epochs may have been initiated and terminated by brane collisions and annihilations. Branes are objects of lower dimensionality embedded in a higher-dimensional matrix. For example, we may live on a three-dimensional brane embedded in a four-dimensional matrix. However, such structures are so far removed from everyday reality that bringing physical insight to bear is difficult. Here we report laboratory experiments where we simulate brane annihilation using the closest brane analogue to which we have access, the coherent phase boundary between the two phases of superfluid He-3. When two branes collide or annihilate, topological defects may be created, whose influence may still be detectable today. By creating a brane-antibrane pair in superfluid He-3 and subsequently annihilating it, we can detect that defects are indeed created in the superfluid texture (the superfluid analogue of spacetime), thus confirming that the concept of defect formation after brane annihilation in the early Universe can be reproduced in analogous systems in the laboratory.

KW - superluid helium-3

KW - braneworld

KW - transitions

KW - topological defects

UR - http://www.scopus.com/inward/record.url?scp=37749043744&partnerID=8YFLogxK

U2 - 10.1038/nphys815

DO - 10.1038/nphys815

M3 - Journal article

VL - 4

SP - 46

EP - 49

JO - Nature Physics

JF - Nature Physics

SN - 1745-2473

IS - 1

ER -