Cosmic Strings
نویسنده
چکیده
Cosmic strings belong to the basic extremals of the Kähler action. The upper bound for string tension of the cosmic strings is T ' .5 × 10−6/G and in the same range as the string tension of GUT strings and this makes them very interesting cosmologically although TGD cosmic strings have otherwise practically nothing to do with their GUT counterparts.
منابع مشابه
Gott-Kaiser-Stebbins (GKS) effect in an accelerated expanding universe
Wewanttofindthecosmologicalconstantinfluenceoncosmicmicrowavebackground(CMB)temperatureduetomovinglinearcosmicstrings.Usingthespace-timemetricofalinearcosmicstringinanacceleratedexpandinguniverse,theGott-Kaiser Stebbins(GKS)effect,asanimportantmechanisminproducingtemperaturediscontinuityinthe(CMB),isconsidered;then,itsmodificationduetotheeffectofthecosmologicalconstantiscalculated.Theresultshowsthat...
متن کاملFermionic Zero Modes of Supergravity Cosmic Strings
Recent developments in string theory suggest that cosmic strings could be formed at the end of brane inflation. Supergravity provides a realistic model to study the properties of strings arising in brane inflation. Whilst the properties of cosmic strings in flat space-time have been extensively studied there are significant complications in the presence of gravity. We study the effects of gravi...
متن کاملThe Revival of Cosmic Strings
Cosmic strings are one-dimensional topological defects which could have been formed in the early stages of our Universe. They triggered a lot of interest, mainly for their cosmological implications: they could offer an alternative to inflation for the generation of density perturbations. It was shown however that cosmic strings lead to inconsistencies with the measurements of the cosmic microwa...
متن کاملar X iv : h ep - t h / 06 04 19 8 v 1 2 7 A pr 2 00 6 Fermionic Zero Modes of Supergravity Cosmic
Recent developments in string theory suggest that cosmic strings could be formed at the end of brane inflation. Supergravity provides a realistic model to study the properties of strings arising in brane inflation. Whilst the properties of cosmic strings in flat space-time have been extensively studied there are significant complications in the presence of gravity. We study the effects of gravi...
متن کاملUltrahigh Energy Cosmic Rays from Topological Defects — Cosmic Strings, Monopoles, Necklaces, and All That
The topological defect scenario of origin of the observed highest energy cosmic rays is reviewed. Under a variety of circumstances, topological defects formed in the early Universe can be sources of very massive particles in the Universe today. The decay products of these massive particles may be responsible for the observed highest energy cosmic ray particles above 10 20 eV. Some massive parti...
متن کامل