7,656 research outputs found
Four-Dimensional String/String Duality
We present supersymmetric soliton solutions of the four-dimensional heterotic
string corresponding to monopoles, strings and domain walls. These solutions
admit the interpretation of a fivebrane wrapped around , or
of the toroidally compactified dimensions and are arguably exact to all
orders in . The solitonic string solution exhibits an {\it
strong/weak coupling} duality which however corresponds to an {\it
target space} duality of the fundamental string.Comment: 14 page
String and M-theory: answering the critics
Using as a springboard a three-way debate between theoretical physicist Lee
Smolin, philosopher of science Nancy Cartwright and myself, I address in
layman's terms the issues of why we need a unified theory of the fundamental
interactions and why, in my opinion, string and M-theory currently offer the
best hope. The focus will be on responding more generally to the various
criticisms. I also describe the diverse application of string/M-theory
techniques to other branches of physics and mathematics which render the whole
enterprise worthwhile whether or not "a theory of everything" is forthcoming.Comment: Update on EPSRC. (Contribution to the Special Issue of Foundations of
Physics: "Forty Years Of String Theory: Reflecting On the Foundations",
edited by Gerard 't Hooft, Erik Verlinde, Dennis Dieks and Sebastian de Haro.
22 pages latex
The membrane at the end of the (de Sitter) universe
The original {\it membrane at the end of the universe} corresponds to a probe
-brane of signature occupying the boundary of
the spacetime , and is described by an
SCFT. However, it was subsequently generalized to other worldvolume
signatures and other spacetime signatures . An interesting
special case is provided by the brane at the end of the de Sitter
universe which has recently featured in the correspondence.
The resulting CFT contains the one recently proposed as the holographic dual of
a four-dimensional de Sitter cosmology.
Supersymmetry restricts by requiring that the corresponding bosonic
symmetry be a subgroup of a superconformal
group. The case of is `doubly holographic' and may be
regarded as the near horizon geometry of -branes or equivalently,
under interchange of conformal and R symmetry, of -branes, provided
. The same correspondence holds in the pp-wave limit of
conventional -theory.Comment: Minor corrections. 20 pages Late
Putting String/Fivebrane Duality to the Test
According to string/fivebrane duality, the Green-Schwarz factorization of the
spacetime anomaly polynomial into means that just
as is the anomaly polynomial of the string worldsheet so
should be the anomaly polynomial of the fivebrane worldvolume. To test
this idea we perform a fivebrane calculation of and find perfect
agreement with the string one--loop result.Comment: 14 pages, CERN TH-6614/92, CTP-TAMU 60/9
Wellbeing in working mothers
Background: Becoming a mother is a period of transition for women and during this period many of them return to work.
Aims: The aim of the study was to explore psychological distress when returning to work after maternity leave. Variables such as work-family conflict, work-family balance, social support and income and their relationship to psychological distress during this period were explored.
Method: 195 women completed an online questionnaire, with demographic questions as well as measures assessing psychological distress, work-family-conflict, work-family-balance and social support. Correlations, t-tests, mediation and moderation analyses were used to explore the results.
Results: Psychological distress was not found to be elevated in mothers returning to work after maternity leave. However, they did have high levels of work-family-conflict and work-family-balance. Social support acted as a mediator of the relationship between work-family-conflict and work-family-balance and psychological distress
Spectrum of D=6, N=4b Supergravity on AdS_3 x S^3
The complete spectrum of D=6, N=4b supergravity with n tensor multiplets
compactified on AdS_3 x S^3 is determined. The D=6 theory obtained from the K_3
compactification of Type IIB string requires that n=21, but we let n be
arbitrary. The superalgebra that underlies the symmetry of the resulting
supergravity theory in AdS_3 coupled to matter is SU(1,1|2)_L x SU(1,1|2)_R.
The theory also has an unbroken global SO(4)_R x SO(n) symmetry inherited from
D=6. The spectrum of states arranges itself into a tower of spin-2
supermultiplets, a tower of spin-1, SO(n) singlet supermultiplets, a tower of
spin-1 supermultiplets in the vector representation of SO(n) and a special
spin-1/2 supermultiplet also in the vector representation of SO(n). The SU(2)_L
x SU(2)_R Yang-Mills states reside in the second level of the spin-2 tower and
the lowest level of the spin-1, SO(n) singlet tower and the associated field
theory exhibits interesting properties.Comment: 37 pages, latex, 5 tables and 3 figures, typos corrected, a reference
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Generalized holonomy of M-theory vacua
The number of M-theory vacuum supersymmetries, 0 <= n <= 32, is given by the
number of singlets appearing in the decomposition of the 32 of SL(32,R) under H
\subset SL(32,R) where H is the holonomy group of the generalized connection
which incorporates non-vanishing 4-form. Here we compute this generalized
holonomy for the n=16 examples of the M2-brane, M5-brane, M-wave, M-monopole,
for a variety of their n=8 intersections and also for the n>16 pp waves.Comment: 24 pages, LaTe
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