black holes,string theory& holography(页 1) - 物理&EE - 太傻超级论坛

coldance 发表于 2006-4-1 17:05

black holes,string theory& holography

Some Journals about [font=Tahoma][color=LimeGreen][size=2]black holes,string theory & holography[/size][/color][/font],Journals hail from [font=Impact][size=3][color=LimeGreen]APS[/color][/size][/font]GfLA&\1@Vs)ne
willing to share more journals about those topics like this with you if u like

coldance 发表于 2006-4-1 17:09

[u] [/u]

coldance 发表于 2006-4-1 17:12

[u] [/u]

coldance 发表于 2006-4-1 19:13

[u] [/u]
[u] [/u]

coldance 发表于 2006-4-1 19:15

[u]
[/u]

coldance 发表于 2006-4-1 19:17

[u]
[/u]

coldance 发表于 2006-4-1 19:22

[u] ~r$`1E&U/bX)]#N\+TF
[/u]

coldance 发表于 2006-4-1 19:26

[u] !L,{8OM @
[/u]

biantian 发表于 2006-4-1 22:12

辛苦楼主了

AlexOrge 发表于 2006-4-2 00:50

回复 #8 coldance 的帖子

辛苦了。

给个介绍吧。

cgyyh 发表于 2006-4-2 01:00

完全没人下？

AlexOrge 发表于 2006-4-2 01:25

回复 #11 cgyyh 的帖子

APS的access大多数学校都有
!p\6a,qanC?V
这些标题罗列叫人怎么下呢？,AKe*^UO.|g~w
s1sl*Ec!vW!Y
所以请楼主介绍一下。

coldance 发表于 2006-4-2 10:19

[quote]原帖由 [i]AlexOrge[/i] 于 2006-4-2 00:50 发表"ve2ZQ S5BSEk
辛苦了。

给个介绍吧。 [/quote]

上面的每个标题都写得很明确的，从标题就应该能看出它们主要是讲些什么的~
其中有些也不是APS的，下面我就按每篇文章的摘要说一下：4G@3Z'vsT v
Q6vOn3i^'aG8B1N
[color=LimeGreen][b]Baby universes in string theory [/b][/color][i]PHYSICAL REVIEW D [/i]73, 066002 (2006) [color=LimeGreen]APS[/color]
We argue that the holographic description of four-dimensional Bogomol’nyi-Prasad-Sommerfield black
holes naturally includes multicenter solutions. This suggests that the holographic dual to the gauge theory
is not a single AdS2×S2 but a coherent ensemble of them. We verify this in a particular class ofW V.FS @
examples, where the two-dimensional Yang-Mills theory gives a holographic description of the black
holes obtained by branes wrapping Calabi-Yau cycles. Using the free fermionic formulation, we show that
O(e-N) nonperturbative effects entangle the two Fermi surfaces. In an Euclidean description, the wave
function of the multicenter black holes gets mapped to the Hartle-Hawking wave function of baby
universes. This provides a concrete realization, within string theory, of effects that can be interpreted as
the creation of baby universes.We find that, at least in the case we study, the baby universes do not lead to
a loss of quantum coherence, in accord with general arguments.%oT&j/i!wE{
%f6Ja_ `6F'L
[color=LimeGreen][b]Holography and compactification[/b][/color] [i]Nuclear Physics B[/i] 580 (2000) 264–274 [color=LimeGreen]Elsevier[/color],@1NM;M FTJ
Following a recent suggestion by Randall and Sundrum, we consider string compactification
scenarios in which a compact slice of AdS-space arises as a subspace of the compactification
manifold. A specific example is provided by the type II orientifold equivalent to type I theory
on (orbifolds of) T 6, upon taking into account the gravitational backreaction of the D3-branesW)B+yX`8r N,\
localized inside the T 6. The conformal factor of the four-dimensional metric depends exponentiallyLDmDc9U
on one of the compact directions, which, via the holographic correspondence, becomes identified2D0O;f0[m9T2?
with the renormalization group scale in the uncompactified world. This set-up can be viewed aseJC;Wy/Y
a generalization of the AdS/CFT correspondence to boundary theories that include gravitational
dynamics. A striking consequence is that, in this scenario, the fundamental Planck size string anddcF.G!?{+]
the large N QCD string appear as (two different wavefunctions of) one and the same object. 1e*e%~2f9\,a
5_!]6erQ(@
[color=LimeGreen][b]PRIMARY SCALAR HAIR OF BLACK HOLES IN EFFECTIVE STRING THEORY[/b][/color]
[i]International Journal of Modern Physics A[/i], Vol. 17, No. 20 (2002) 2768 [color=LimeGreen]World Scientific Publishing Company[/color]h-\(rM7YI1_[W
Black holes in string theories can be studied by means of effective gravity-matter actions.~W9rbV2DK
These contain, among others, non-minimally coupled scalar fields, as the dilaton and{%WKXH3]4p
moduli arising from the compactification of the extra dimensions. The presence of nonminimalM2k!}Un*J&p%P'p#}_
couplings prevents the application of the well known no-hair theorems, so
that it is possible to find regular black hole solutions with scalar hair. Solutions with
non-trivial dilaton hair are known for [color=LimeGreen]Maxwell and Gauss-Bonnet black holes[/color]. In these;on4V-n3^!M_
cases the dilaton charge is a function of the other parameters of the solutions (secondary0b!A-YT Pg?)IQ*@-P
hair). However, it has recently been shown that when moduli fields are taken into account
as well, one can obtain solutions where the scalar charges of the moduli are independent^hp~)M u!a'|
parameters (primary scalar hair). The thermodynamics of these black holes has been
investigated. In particular, in the Maxwell case a condition for extremality has been
obtained, which sets a lower bound for the mass in terms of the magnetic and scalar
charges. Similarly in the Gauss-Bonnet case, a minimal allowed value for the mass has3[-@8_iS5\
been found, which depends only on the scalar charges and can be interpreted as a ground7F!n eG/Opf
state for the Hawking evaporation process of the black hole.
+b5A"`6YkyszN
O1F6AaH `,LZ
[b][color=LimeGreen]Bose-Einstein condensation at constant temperature[/color][/b] [i]PHYSICAL REVIEW A[/i] 70, 031602(R) (2004) [color=LimeGreen]APS[/color]
We present an experimental approach to Bose-Einstein condensation by increasing the particle number of the
system at almost constant temperature. In particular, the emergence of a new condensate is observed in)_(qhE%rW0x4r
multicomponent [i]F=1[/i] spinor condensates of 87Rb. Furthermore, we develop a simple rate-equation model for1H$n8e$eU!|k.P
multicomponent Bose-Einstein condensate thermodynamics at finite temperature which well reproduces the
measured effects.0uJ/WBj6w({A

KE:`@9Jb
[color=LimeGreen][b]Luttinger Liquid of Polarons in One-Dimensional Boson-Fermion Mixtures[/b][/color]
[i]PHYSICA L REVIEW LETTERS [/i]  04/[b]93[/b](12)/120404(4) [color=LimeGreen]APS[/color]
We use the bosonization approach to investigate quantum phases of boson-fermion mixtures (BFM)
of atoms confined to one dimension by an anisotropic optical lattice. For a BFM with a single species ofCd;?'J:GuT
fermions we find a charge-density wave phase, a fermion pairing phase, and a phase separation regime.
We also obtain the rich phase diagram of a BFM with two species of fermions. We demonstrate that
these phase diagrams can be understood in terms of polarons, i.e., atoms ‘‘dressed’’ by screening clouds
of the other atom species. Techniques to detect the resulting quantum phases are discussed.*}:xF9j J`VAV
,Llat7Nh(iEm1F
wTaGE&]QW-o
[color=LimeGreen][b]Black hole-neutron star binaries in general relativity: Quasiequilibrium formulation[/b][/color]
[i]PHYSICAL REVIEW D[/i],0556-2821=2004=70(6)=064040(18) [color=LimeGreen]APS[/color]/T)~)AJ)k$T:yV
We present a new numerical method for the construction of quasiequilibrium models of black holeneutron
star binaries. We solve the constraint equations of general relativity, decomposed in the
conformal thin-sandwich formalism, together with the Euler equation for the neutron star matter.
We take the system to be stationary in a corotating frame and thereby assume the presence of a helical
Killing vector.We solve these coupled equations in the background metric of a Kerr-Schild black hole,
which accounts for the neutron star’s black hole companion. In this paper we adopt a polytropic T`^ O-Pq$x"p
equation of state for the neutron star matter and assume large black hole-to-neutron star mass ratios.
These simplifications allow us to focus on the construction of quasiequilibrium neutron star models inH{8BSF'o3?
the presence of strong-field, black hole companions. We summarize the results of several code tests,
compare with Newtonian models, and locate the onset of tidal disruption in a fully relativisticxi.giZ
framework.

[color=LimeGreen][b]Charged rotating black holes on a 3-brane[/b][/color]
[i]PHYSICAL REVIEW D[/i] 71, 104027 (2005) [color=LimeGreen]APS[/color]
We study exact stationary and axisymmetric solutions describing charged rotating black holes localizedB]*k-wF V
on a 3-brane in the Randall-Sundrum braneworld. The charges of the black holes are considered to be of ]#^p9D`3K&C7O
two types, the first being an induced tidal charge that appears as an imprint of nonlocal gravitational
effects from the bulk space and the second is a usual electric charge arising due to a Maxwell field trapped0h)zc ZZ
on the brane.We assume a special ansatz for the metric on the brane taking it to be of the Kerr-Schild form-Wj yPnQ4Uo-t
and show that the Kerr-Newman solution of ordinary general relativity in which the electric charge isb2y-fS^(oy6j g
superseded by a tidal charge satisfies a closed system of the effective gravitational field equations on the8J3L\S,Y0aZL+}"Y
brane. It turns out that the negative tidal charge may provide a mechanism for spinning up the black hole
so that its rotation parameter exceeds its mass. This is not allowed in the framework of general relativity.
We also find a new solution that represents a rotating black hole on the brane carrying both charges. We
show that for a rapid enough rotation the combined influence of the rotational dynamics and the local bulk
effects of the ‘‘squared’’ energy-momentum tensor on the brane distort the horizon structure of the black
hole in such a way that it can be thought of as composed of nonuniformly rotating null circles withD&pc[8uW\,Q
growing radii from the equatorial plane to the poles. We finally study the geodesic motion of test particles
in the equatorial plane of a rotating black hole with tidal charge. We show that the effects of negative tidal'q!d K9?1VQ%B
charge tend to increase the horizon radius, as well as the radii of the limiting photon orbit, the innermost
bound and the innermost stable circular orbits for both direct and retrograde motions of the particles.rz-cr0`8d+u Q

[color=LimeGreen][b]Holographic Entropy Bound and Local Quantum Field Theory[/b][/color]3@n#l ^6vAG*E;Ge
[i]PHYSICA L REVIEW LETTERS[/i] 0031-9007=03=91(4)=041302(4)$20.00 |$Z4I9i,@j b P5Ok$~
I show how the holographic entropy bound can be derived from elementary flat-spacetime quantum#xc,VMA@
field theory when the total energy of Fock states is constrained gravitationally. This energy constraint6j!DLO#^
makes the Fock space dimension (whose logarithm is the maximum entropy) finite for both bosons andf{\+_wS3tzv3l
fermions. Despite the elementary nature of my analysis, it results in an upper limit on entropy ino;Y9G{'}jv
remarkable agreement with the holographic bound, and also provides a microscopic deviation of a more
general entropy bound recently introduced by Gour.
D:KwpZ'q8j
[color=LimeGreen][b]Improved constraints on supersymmetric dark matter from muon g-2[/b][/color]
[i]PHYSICAL REVIEW D[/i] 67, 063503 (2003) [color=LimeGreen]APS[/color]Q"O.O2u2g0f,cu+Z
The new measurement of the anomalous magnetic moment of the muon by the Brookhaven AGS experimentP A8|Kx#msr Y
821 again shows a discrepancy with the standard model value. We investigate the consequences of these newa-u~9H{]N
data for neutralino dark matter, updating and extending our previous work [[color=LimeGreen]E. A. Baltz and P. Gondolo, Phys.Rev. Lett. 86, 5004(2001)[/color]]. The measurement excludes the standard model value at 3.0 s confidence, assuming the evaluation using the hadronic e+e- cross section (the τ decay evaluation yields only a 1.6σ discrepancy).We analyze a phenomenological set of supersymmetric models with gaugino mass unification imposed butCZ2~ qk5{}
without a priori constraints on the Higgs sector. Taking the discrepancy as a sign of supersymmetry, we find0Vf9E(E7@P-I
that the lightest superpartner must be relatively light and it must have a relatively high elastic scattering cross'\*^ n`hN] h
section with nucleons, which brings it almost within reach of proposed direct dark matter searches. The SUSY
signal from neutrino telescopes correlates fairly well with the elastic scattering cross section. The rate of
cosmic ray antideuterons tends to be large in the allowed models, but the constraint has little effect on the rate
of gamma ray lines. We stress that being more conservative may eliminate the discrepancy, but it does not
eliminate the possibility of high astrophysical detection rates.WRpUGq
l:WX!xf\7[:t$}
[color=LimeGreen][b]Measurement of CP observables for the decays B±→D[/b][/color][size=-2][b]CP[/b][/size][color=LimeGreen][b]0K±[/b][/color]
[i]PHYSICAL REVIEW D[/i] 73, 051105(R) (2006) [color=LimeGreen]APS[/color]

[color=LimeGreen][b]Observational constraints on braneworld inflation: The effect of a Gauss-Bonnet term[/b][/color]WZ6X(t'eoniz+G
[i]PHYSICAL REVIEW D[/i], VOLUME 70, 063525 [color=LimeGreen]APS[/color]C]2U+_KZ-nPbP
High-energy modifications to general relativity introduce changes to the perturbations generatedI7kk"f#H5O
during inflation, and the latest high-precision cosmological data can be used to place constraints on suchbU^?TZ3Y
modified inflation models. Recently it was shown that Randall-Sundrum–type braneworld inflation
leads to tighter constraints on quadratic and quartic potentials than in general relativity.We investigate!NCT\/f ]n.[r
how this changes with a Gauss-Bonnet correction term, which can be motivated by string theory.
Randall-Sundrum models preserve the standard consistency relation between the tensor spectral indexst7`6T N Q
and the tensor-to-scalar ratio. The Gauss-Bonnet term breaks this relation, and also modifies the5\l!iI4w*}1NM
dynamics and perturbation amplitudes at high energies. We find that the Gauss-Bonnet term tends toe8R,B0gQ'kq w
soften the Randall-Sundrum constraints. The observational compatibility of the quadratic potential is.KTXt;j'?}y
strongly improved. For a broad range of energy scales, the quartic potential is rescued from marginaldVeJ4Q5b.p
rejection. Steep inflation driven by an exponential potential is excluded in the Randall-Sundrum case, h(i5H;[zV#a\u5F
but the Gauss-Bonnet term leads to marginal compatibility for sufficient e-folds.

[color=LimeGreen][b]Spacetime structure of static solutions in Gauss-Bonnet gravity: Neutral case[/b][/color]^k{Gm7M/T\O7`n
[i]PHYSICAL REVIEW D[/i] 71, 124002 (2005) [color=LimeGreen]APS[/color]V0l0cKmd
We study the spacetime structures of the static solutions in the n-dimensional Einstein-Gauss-Bonnet-%Rrw{c
system systematically. We assume the Gauss-Bonnet coefficient α is non-negative and a cosmological
constant is either positive, zero, or negative. The solutions have the (n-2)-dimensional Euclideanz;UvO8Kb6{Y
submanifold, which is the Einstein manifold with the curvature k=1, 0, and -1. We also assumeC#Zd1R5a1X@+GJ6l
4α/ι2≤1, where ι is the curvature radius, in order for the sourceless solution (M=0) to be defined. The
general solutions are classified into plus and minus branches. The structures of the center, horizons,
infinity, and the singular point depend on the parameters α,ι2, k, M, and branches complicatedly so that a
variety of global structures for the solutions are found. In our analysis, the ~M-r diagram is used, which
makes our consideration clear and enables easy understanding by visual effects.0w0I7u,vwx

[color=LimeGreen][b]The power of general relativity[/b][/color] [i]PHYSICAL REVIEW D[/i] 72, 103005 (2005)  [color=LimeGreen]APS[/color] We study the cosmological and weak-field properties of theories of gravity derived by extending
general relativity by means of a Lagrangian proportional to R^1+δ. This scale-free extension reduces to6hjWf/\e [
general relativity when δ→0. In order to constrain generalizations of general relativity of this powerX,s'|g ka M'E
class, we analyze the behavior of the perfect-fluid Friedmann universes and isolate the physically relevantZ;i#_H*Si Hr{ b
models of zero curvature. A stable matter-dominated period of evolution requires δ>0 or δ<-1/4. TheZ'?LUe&{@%UD
stable attractors of the evolution are found. By considering the synthesis of light elements (helium-4,j_fgzX#u
deuterium and lithium-7) we obtain the bound -0.017<δ<0.0012.We evaluate the effect on the power'a&s9h n_G$XQ I
spectrum of clustering via the shift in the epoch of matter-radiation equality. The horizon size at matterradiation
equality will be shifted by ~1% for a value of δ~0.0005. We study the stable extensions of the
Schwarzschild solution in these theories and calculate the timelike and null geodesics. No significant'K uLc(Y Q"h
bounds arise from null geodesic effects but the perihelion precession observations……&\&bRN.i

[color=LimeGreen][b]VIRTUAL BLACK HOLES AND THE S-MATRIX[/b][/color]8K1fh$L"fQ6v
[i]International Journal of Modern Physics D[/i] Vol. 13, No. 10 (2004) 1973~2001  [color=LimeGreen]World Scientific Publishing Company[/color]
A brief review on virtual black holes is presented, with special emphasis on phenomenologically5k*sX7]!or9Sd1B
relevant issues like their inuence on scattering or on the specific heat of (real)
black holes. Regarding theoretical topics, the results important for (the avoidance of)6v$c/|)D5^HN
information loss are summarized.2stP5mB ey
After recalling [color=LimeGreen]Hawking's Euclidean notion [/color]of virtual black holes and a Minkowskian
notion which emerged in studies of 2D models, the importance of virtual black holes forI ]l$RW$l@&win!c
scattering experiments is addressed. Among the key features is that virtual black holes
tend to regularize divergences of quantum eld theory and that a unitary S-matrix may
be constructed. Also, the thermodynamical behavior of real evaporating black holes~f3@M~6K
may be ameliorated by interactions with virtual black holes. Open experimental and
theoretical challenges are mentioned briefly.t;b{$c#NG8UId
Keywords: Virtual black holes; information paradox; quantum gravity; 2D dilaton gravity.

coldance 发表于 2006-4-2 10:23

以上每个摘要都是按附件的顺序来的~
上下角标因为在论坛上不好排，而显得不是很明了

coldance 发表于 2006-4-2 10:26

~但原文上都是很明了的~

AlexOrge 发表于 2006-4-2 12:27

回复 #13 coldance 的帖子

support

觉主发表于 2006-4-2 17:02

支持~~
超弦确实是很有意思的领域不过要拼命学很多数学

coldance 发表于 2006-4-2 18:59

楼上的讲的很对！
毕竟，一般来讲，自然科学跟数学都是分不开的，物理更是如此～7Q(qWK,](Ad4D3[
J |6qu+v~T
[[i] 本帖最后由 coldance 于 2006-4-5 08:39 编辑 [/i]]

cgyyh 发表于 2006-4-2 21:09

辛苦了

hndyf 发表于 2006-4-5 12:30

辛苦了。

haieryu 发表于 2006-4-9 23:32

支持！！！

coldance 发表于 2006-4-15 13:14

Particles and relativityCcO4Qs)q
In the 18th and 19th centuries, Newton's mathematical description of motion using calculus and his model for the gravitational force were extended very successfully to the emerging science and technology of electromagnetism. Calculus evolved into classical field theory.
Once electromagnetic fields were thoroughly described using mathematics, many physicists felt that the field was finished, that there was nothing left to describe or explain.
Then the electron was discovered, and particle physics was born. Through the mathematics of quantum mechanics and experimental observation, it was deduced that all known particles fell into one of two classes: bosons or fermions. Bosons are particles that transmit forces. Many bosons can occupy the same state at the same time. This is not true for fermions, only one fermion can occupy a given state at a given time, and this is why fermions are the particles that make up matter. This is why solids can't pass through one another, why we can't walk through walls -- because of Pauli repulsion -- the inability of fermions (matter) to share the same space the way bosons (forces) can.
While particle physics was developing with quantum mechanics, increasing observational evidence indicated that light, as electromagnetic radiation, travelled at one fixed speed (in a vacuum) in every direction, according to every observer. This discovery and the mathematics that Einstein developed to describe it and model it in his Special Theory of Relativity, when combined with the later development of quantum mechanics, gave birth to the rich subject of relativistic quantum field theory. Relativistic quantum field theory is the foundation of our present theoretical ability to describe the behavior of the subatomic particles physicists have been observing and studying in the latter half of the 20th century.
But Einstein then extended his Special Theory of Relativity to encompass Newton's theory of gravitation, and the result, Einstein's General Theory of Relativity, brought the mathematics called differential geometry into physics. Zj#U@%d~,a6c%N
General relativity has had many observational successes that proved its worth as a description of Nature, but two of the predictions of this theory have staggered the public and scientific imaginations: the expanding Universe, and black holes. Both have been observed, and both encapsulate issues that, at least in the mathematics, brush up against the very nature of reality and existence.

coldance 发表于 2006-4-15 13:15

What is string theory?

Think of a guitar string that has been tuned by stretching the string under tension across the guitar. Depending on how the string is plucked and how much tension is in the string, different musical notes will be created by the string. These musical notes could be said to be excitation modes of that guitar string under tension. H/x)gOrrs
In a similar manner, in string theory, the elementary particles we observe in particle accelerators could be thought of as the "musical notes" or excitation modes of elementary strings. -t9]$C4w9T@
In string theory, as in guitar playing, the string must be stretched under tension in order to become excited. However, the strings in string theory are floating in spacetime, they aren't tied down to a guitar. Nonetheless, they have tension. The string tension in string theory is denoted by the quantity 1/(2 p a'), where a' is pronounced "alpha prime"and is equal to the square of the string length scale. BVR7d(?/d7h;r+X
If string theory is to be a theory of quantum gravity, then the average size of a string should be somewhere near the length scale of quantum gravity, called the Planck length, which is about 10-33 centimeters, or about a millionth of a billionth of a billionth of a billionth of a centimeter. Unfortunately, this means that strings are way too small to see by current or expected particle physics technology (or financing!!) and so string theorists must devise more clever methods to test the theory than just looking for little strings in particle experiments. 8nUt$f])d'h
String theories are classified according to whether or not the strings are required to be closed loops, and whether or not the particle spectrum includes fermions. In order to include fermions in string theory, there must be a special kind of symmetry called supersymmetry, which means for every boson (particle that transmits a force) there is a corresponding fermion (particle that makes up matter). So supersymmetry relates the particles that transmit forces to the particles that make up matter. `k*ilx
Supersymmetric partners to to currently known particles have not been observed in particle experiments, but theorists believe this is because supersymmetric particles are too massive to be detected at current accelerators. Particle accelerators could be on the verge of finding evidence for high energy supersymmetry in the next decade. Evidence for supersymmetry at high energy would be compelling evidence that string theory was a good mathematical model for Nature at the smallest distance scales.

coldance 发表于 2006-4-15 13:16

Why strings ?

Relativistic quantum field theory has worked very well to describe the observed behaviors and properties of elementary particles. But the theory itself only works well when gravity is so weak that it can be neglected. Particle theory only works when we pretend gravity doesn't exist. :}Dz%g"D2co
General relativity has yielded a wealth of insight into the Universe, the orbits of planets, the evolution of stars and galaxies, the Big Bang and recently observed black holes and gravitational lenses. However, the theory itself only works when we pretend that the Universe is purely classical and that quantum mechanics is not needed in our description of Nature. t0^f.mL6S7V
String theory is believed to close this gap. UR/^7^:t0F6dz
Originally, string theory was proposed as an explanation for the observed relationship between mass and spin for certain particles called hadrons, which include the proton and neutron. Things didn't work out, though, and Quantum Chromodynamics eventually proved a better theory for hadrons. aS FV~M3q8}
But particles in string theory arise as excitations of the string, and included in the excitations of a string in string theory is a particle with zero mass and two units of spin.
If there were a good quantum theory of gravity, then the particle that would carry the gravitational force would have zero mass and two units of spin. This has been known by theoretical physicists for a long time. This theorized particle is called the graviton. Q[T:FK+h|~vR
This led early string theorists to propose that string theory be applied not as a theory of hadronic particles, but as a theory of quantum gravity, the unfulfilled fantasy of theoretical physics in the particle and gravity communities for decades. &Tl {J/Mg%F&lJOK@o
But it wasn't enough that there be a graviton predicted by string theory. One can add a graviton to quantum field theory by hand, but the calculations that are supposed to describe Nature become useless. This is because, as illustrated in the diagram above, particle interactions occur at a single point of spacetime, at zero distance between the interacting particles. For gravitons, the mathematics behaves so badly at zero distance that the answers just don't make sense. In string theory, the strings collide over a small but finite distance, and the answers do make sense.
This doesn't mean that string theory is not without its deficiencies. But the zero distance behavior is such that we can combine quantum mechanics and gravity, and we can talk sensibly about a string excitation that carries the gravitational force.
This was a very great hurdle that was overcome for late 20th century physics, which is why so many young people are willing to learn the grueling complex and abstract mathematics that is necessary to study a quantum theory of interacting strings.

coldance 发表于 2006-4-15 13:18

What is theoretical physics ?

Theoretical physicists use mathematics to describe certain aspects of Nature. Sir Isaac Newton was the first theoretical physicist, although in his own time his profession was called "natural philosophy".
By Newton's era people had already used algebra and geometry to build marvelous works of architecture, including the great cathedrals of Europe, but algebra and geometry only describe things that are sitting still. In order to describe things that are moving or changing in some way, Newton invented calculus. ZU{d2}i)h9Ys
The most puzzling and intriguing moving things visible to humans have always been been the sun, the moon, the planets and the stars we can see in the night sky. Newton's new calculus, combined with his "Laws of Motion", made a mathematical model for the force of gravity that not only described the observed motions of planets and stars in the night sky, but also of swinging weights and flying cannonballs in England.
Today's theoretical physicists are often working on the boundaries of known mathematics, sometimes inventing new mathematics as they need it, like Newton did with calculus. 9R s[#Y^Z`
Newton was both a theorist and an experimentalist. He spent many many long hours, to the point of neglecting his health, observing the way Nature behaved so that he might describe it better. The so-called "Newton's Laws of Motion" are not abstract laws that Nature is somehow forced to obey, but the observed behavior of Nature that is described in the language of mathematics. In Newton's time, theory and experiment went together.
Today the functions of theory and observation are divided into two distinct communities in physics. Both experiments and theories are much more complex than back in Newton's time. Theorists are exploring areas of Nature in mathematics that technology so far does not allow us to observe in experiments. Many of the theoretical physicists who are alive today may not live to see how the real Nature compares with her mathematical description in their work. Today's theorists have to learn to live with ambiguity and uncertainty in their mission to describe Nature using math.

coldance 发表于 2006-4-18 16:01

1999诺贝尔物理奖得主赫拉尔杜斯·霍夫特制作的自学理论物理的网站

[url]http://www.phys.uu.nl/~thooft/theorist.html[/url]~prRu sX
%Md8~L1i4OrNGU{%F
ON How to Become a Good Theoretical Physicist ?
This site is a guide for the aspiring or amateur theoretical physicist, authored by Nobel Prize winner [color=LimeGreen]Gerardus 't Hooft[/color], Institute for Theoretical Physics, University of [color=LimeGreen]Utrecht[/color]. The author gives his advice on becoming a physicist and brings together a list of Internet educational resources from various sources to produce a virtual course in physics outlined and linked on this page.
Additionally,the author [color=Teal]Gerardus 't Hooft[/color] share the Nobel Prize with his teacher [color=Teal]Martinus JG Veltman[/color] for the contribution of [color=LimeGreen]elucidating the quantum structure of electroweak interactions in physics[/color].4S6Gf1NN&}v

[[i] 本帖最后由 coldance 于 2006-4-18 16:02 编辑 [/i]]

coldance 发表于 2006-4-18 16:07

Martinus JG Veltman 简介...

--------------------------------------------------------------------------------3Q'y1VI \9F,I?|
　马丁努斯·J·G·韦尔特曼1931年生于荷兰。1963年获得乌得勒支大学物理学博士学位。1966－1981年在乌得勒支大学任物理学教授。1981年成为荷兰科学院院士，同年任教于美国密歇根大学。1993年获得欧洲物理学会颁发的高能和粒子物理奖。
　　韦尔特曼和他的学生赫拉尔杜斯·霍夫特因70年代作出的“阐明物理学中电弱相互作用的量子结构”方面的理论研究成就而获得1999年度诺贝尔物理奖。他们的计算理论使粒子物理有了更牢固的数学基础，尤其是可以用他们的理论来更精确计算物理量。
　　众所周知，构成物质的原子是由电子和原子核组成，原子核由质子和中子组成，后二者又由更小的粒子夸克组成。为了研究夸克，50年代制成了第一台加速器，这标志着现代粒子物理学的诞生，科学家首次可以研究如何轰出新的粒子及其物理性质。在此基础上物理学家们提出了粒子物理的标准模型，它将所有基本粒子分为夸克、轻子和互换粒子三类，前二者在后者的参与下产生强力和弱力。但是最初物理学家们还不能用完整的数学理论来描述这个模型，因此很多人对进一步发展该理论感到悲观。但是，韦尔特曼教授没有灰心，从1969年起他和他的只有22岁的学生霍夫特一起进行研究，最终取得了突破。在他们1971年的文章中成功地严格证明电弱统一理论是可以经过“重整化”而消除其中所有的“无穷大”的，从而证明弱相互作用也能和电磁相互作用一样地进行精确计算，也可以接受实验的精确检验。这是人们对弱相互作用了解的一个飞跃。自那时起，人们不断用他们的理论方法对电弱统一理论进行精确计算，做了大量预言。同时，在欧洲核子研究中心的大型正负电子对撞机LEP上也对大量电弱相互作用过程进行了精确测量。近年的分析表明理论与实验符合得非常好。电弱统一理论成为本世纪物理学发展的一项十分重大的划时代的成就。理论与实验的比较还预言了顶夸克（当时还未发现的第6种夸克）的质量为171.4GeV左右。后来在美国的费米实验室找到了顶夸克，直接测量的顶夸克质量为174.3GeV左右，与上述预言相符甚好。这也是电弱统一理论精确计算的一大成功。
　　目前在电弱统一理论中还有一个关键的问题没弄清楚。Higgs场至今还未在实验中找到。由于探索真空中的物质涉及人们对一切物质的质量起源的了解，所以它是人们现在最关注的高能物理研究的前沿课题。

coldance 发表于 2006-4-18 16:09

Gerardus 't Hooft 简介...

--------------------------------------------------------------------------------J(A1G/?h2N"mD8`z
　赫拉尔杜斯·霍夫特1946年生于荷兰登海尔德。1972年在乌得勒支大学获得物理学博士学位。1977年起在乌得勒支大学任物理学教授。1979年获得美国物理学会丹尼－海涅曼奖。1982年获得沃尔夫奖，同年成为荷兰科学院院士。
　　霍夫特和他的老师韦尔特曼因70年代作出的“阐明物理学中电弱相互作用的量子结构”方面的理论研究成就而获得1999年度诺贝尔物理奖。他们的计算理论使粒子物理有了更牢固的数学基础，尤其是可以用他们的理论来更精确计算物理量。
　　众所周知，构成物质的原子是由电子和原子核组成，原子核由质子和中子组成，后二者又由更小的粒子夸克组成。为了研究夸克，50年代制成了第一台加速器，这标志着现代粒子物理学的诞生，科学家首次可以研究如何轰出新的粒子及其物理性质。在此基础上物理学家们提出了粒子物理的标准模型，它将所有基本粒子分为夸克、轻子和互换粒子三类，前二者在后者的参与下产生强力和弱力。但是最初物理学家们还不能用完整的数学理论来描述这个模型，因此很多人对进一步发展该理论感到悲观。但是年仅22岁的霍夫特在他的老师韦尔特曼指导下，从1969年开始进行了不懈的研究，最终取得了突破。在他们1971年的文章中成功地严格证明电弱统一理论是可以经过“重整化”而消除其中所有的“无穷大”的，从而证明弱相互作用也能和电磁相互作用一样地进行精确计算，也可以接受实验的精确检验。这是人们对弱相互作用了解的一个飞跃。自那时起，人们不断用他们的理论方法对电弱统一理论进行精确计算，做了大量预言。同时，在欧洲核子研究中心的大型正负电子对撞机LEP上也对大量电弱相互作用过程进行了精确测量。近年的分析表明理论与实验符合得非常好。电弱统一理论成为本世纪物理学发展的一项十分重大的划时代的成就。理论与实验的比较还预言了顶夸克（当时还未发现的第6种夸克）的质量为171.4GeV左右。后来在美国的费米实验室找到了顶夸克，直接测量的顶夸克质量为174.3GeV左右，与上述预言相符甚好。这也是电弱统一理论精确计算的一大成功。 sZYwC~n
　　目前在电弱统一理论中还有一个关键的问题没弄清楚。Higgs场至今还未在实验中找到。由于探索真空中的物质涉及人们对一切物质的质量起源的了解，所以它是人们现在最关注的高能物理研究的前沿课题。

set_sail1981 发表于 2006-4-21 11:46

辛苦了！

辛苦了！是呀数学很重要的！

development 发表于 2006-4-22 12:20

在学粒子物理,
超弦就.......强人学的东西

passager 发表于 2006-4-24 14:20

下载了楼主提供的资料，谢谢

coldance 发表于 2006-4-27 10:21

再传一些。。。

...[u]
[/u]

[[i] 本帖最后由 coldance 于 2006-4-27 10:26 编辑 [/i]]

coldance 发表于 2006-4-27 10:29

[u]
[/u]

[[i] 本帖最后由 coldance 于 2006-4-27 10:50 编辑 [/i]]

cgyyh 发表于 2006-4-27 13:21

听名字就喜欢。
不过这些牛的文章怎么都这么长捏。

cgyyh 发表于 2006-4-27 13:29

那个rar文件有问题，你能不能把它转换成pdf下。
那个ps好像有错。

coldance 发表于 2006-4-27 15:09

[quote]原帖由 [i]cgyyh[/i] 于 2006-4-27 13:29 发表 Ouf gz Ymj
那个rar文件有问题，你能不能把它转换成pdf下。
那个ps好像有错。 [/quote]&w-@o#zlgqx
'VSOHSR8_AYX
这个...把 ps文件转换为 pdf的我还不会::823h8D#{Y0O2h5Yq7IB
恳请牛人的帮助```

cgyyh 发表于 2006-4-27 15:31

回复 #36 coldance 的帖子

有acrobat professional吗，然后打印就行了。
估计是文件本来就坏了。你怎么下ps呢。直接下pdf不就好了。

cgyyh 发表于 2006-4-27 20:17

I got it。

coldance 发表于 2006-4-28 09:46

[quote]原帖由 [i]cgyyh[/i] 于 2006-4-27 20:17 发表4[8UI8n)t"}?
I got it。 [/quote]/bfR/{gu$rc
谢谢你的补充和支持。。。3\M}tA*\9i
希望这些能对我们学习(理解)弦论有所帮助...

znithy 发表于 2006-5-26 12:23

THX 都要了哈哈

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