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{{About|the possible causal relationships among points in a Lorentzian manifold|classification of Lorentzian manifolds according to the types of causal structures they admit|Causality conditions}}
{{Merge|Causality conditions|date=July 2010}}
 
In [[mathematical physics]], the '''causal structure''' of a [[Lorentzian manifold]] describes the [[Causality (physics)|causal relationships]] between points in the manifold.
 
== Introduction ==
 
In modern physics (especially [[general relativity]]) [[spacetime]] is represented by a [[Lorentzian manifold]]. The causal relations between points in the manifold are interpreted as describing which events in spacetime can influence which other events.
 
[[Minkowski spacetime]] is a simple example of a Lorentzian manifold. The causal relationships between points in Minkowski spacetime take a particularly simple form since the space is [[curvature|flat]]. See [[Minkowski space#Causal structure|Causal structure of Minkowski spacetime]] for more information.
 
The causal structure of an arbitrary (possibly curved) Lorentzian manifold is made more complicated by the presence of [[curvature]]. Discussions of the causal structure for such manifolds must be phrased in terms of [[smooth function|smooth]] [[curve]]s joining pairs of points. Conditions on the [[tangent vectors]] of the curves then define the causal relationships.
 
=== Tangent vectors ===
 
If <math>\,(M,g)</math> is a [[Lorentzian manifold]] (for [[metric tensor|metric]] <math>g</math> on [[manifold]] <math>M</math>) then the tangent vectors at each point in the manifold can be classed into three different types.
A tangent vector <math>X</math> is
* '''timelike''' if <math>\,g(X,X) > 0</math>
* '''null''' if <math>\,g(X,X) = 0</math>
* '''spacelike''' if <math>\,g(X,X) < 0</math>
(Here we use the <math>(+,-,-,-,\cdots)</math> [[metric signature]]). A tangent vector is called "non-spacelike" if it is null or timelike.
 
These names come from the simpler case of Minkowski spacetime (see [[Minkowski space#Causal structure|Causal structure of Minkowski spacetime]]).
 
=== Time-orientability ===
 
At each point in <math>M</math> the timelike tangent vectors in the point's [[tangent space]] can be divided into two classes. To do this we first define an [[equivalence relation]] on pairs of timelike tangent vectors.
 
If <math>X</math> and <math>Y</math> are two timelike tangent vectors at a point we say that <math>X</math> and <math>Y</math> are equivalent (written <math>X \sim Y</math>) if <math>\,g(X,Y) > 0</math>.
 
There are then two [[equivalence class]]es which between them contain all timelike tangent vectors at the point.
We can (arbitrarily) call one of these equivalence classes "future-directed" and call the other "past-directed". Physically this designation of the two classes of future- and past-directed timelike vectors corresponds to a choice of an [[arrow of time]] at the point. The future- and past-directed designations can be extended to null vectors at a point by continuity.
 
A [[Lorentzian manifold]] is '''time-orientable'''<ref>{{harvnb|Hawking|Israel|1979|p=255}}</ref> if a continuous designation of future-directed and past-directed for non-spacelike vectors can be made over the entire manifold.
 
=== Curves ===
 
A '''path''' in <math>M</math> is a [[Smooth_function#Parametric_continuity|continuous]] map <math>\mu : \Sigma \to M</math> where <math>\Sigma</math> is a nondegenerate interval (i.e., a connected set containing more than one point) in <math>\mathbb{R}</math>. A '''smooth''' path has <math>\mu</math> differentiable an appropriate number of times (typically <math>C^\infty</math>), and a '''regular''' path has nonvanishing derivative.
 
A '''curve''' in <math>M</math> is the image of a path or, more properly, an equivalence class of path-images related by re-parametrisation, i.e. [[homeomorphism]]s or [[diffeomorphism]]s of <math>\Sigma</math>.  When <math>M</math> is time-orientable, the curve is '''oriented''' if the parameter change is required to be [[monotonic function|monotonic]].
 
Smooth regular curves (or paths) in <math>M</math> can be classified depending on their tangent vectors. Such a curve is
* '''chronological''' (or '''timelike''') if the tangent vector is timelike at all points in the curve.
* '''null''' if the tangent vector is null at all points in the curve.
* '''spacelike''' if the tangent vector is spacelike at all points in the curve.
* '''causal''' (or '''non-spacelike''') if the tangent vector is timelike ''or'' null at all points in the curve.
The requirements of regularity and nondegeneracy of <math>\Sigma</math> ensure that closed causal curves (such as those consisting of a single point) are not automatically admitted by all spacetimes.
 
If the manifold is time-orientable then the non-spacelike curves can further be classified depending on their orientation with respect to time.
 
A chronological, null or causal curve in <math>M</math> is
* '''future-directed''' if, for every point in the curve, the tangent vector is future-directed.
* '''past-directed''' if, for every point in the curve, the tangent vector is past-directed.
These definitions only apply to causal (chronological or null) curves because only timelike or null tangent vectors can be assigned an orientation with respect to time.
 
* A '''closed timelike curve''' is a closed curve which is everywhere future-directed timelike (or everywhere past-directed timelike).
* A '''closed null curve''' is a closed curve which is everywhere future-directed null (or everywhere past-directed null).
 
* The holonomy of the ratio of the rate of change of the affine parameter around a closed null geodesic is the '''redshift factor'''.
 
=== Causal relations ===
 
There are two types of causal [[relation (mathematics)|relations]] between points <math>x</math> and <math>y</math> in the manifold <math>M</math>.
 
* <math>x</math> '''chronologically precedes''' <math>y</math> (often denoted <math>\,x \ll y</math>) if there exists a future-directed chronological (timelike) curve from <math>x</math> to <math>y</math>.
 
* <math>x</math> '''causally precedes''' <math>y</math> (often denoted <math>x \prec y</math> or <math>x \le y</math>)  if there exists a future-directed causal (non-spacelike) curve from <math>x</math> to <math>y</math> or <math>x=y</math>.
 
* <math>x</math> '''strictly causally precedes''' <math>y</math> (often denoted <math>x < y</math>) if there exists a future-directed causal (non-spacelike) curve from <math>x</math> to <math>y</math>.
 
* <math>x</math> '''horismos''' <math>y</math><ref>{{harvnb|Penrose|1972|p=15}}</ref> (often denoted <math>x \to y</math> or <math> x \nearrow y </math>) if <math>x \prec y</math> and <math>x \not\ll y</math>.
 
These relations are [[transitive relation|transitive]]:<ref name = "Penrose12">{{harvnb|Penrose|1972|p=12}}</ref>
* <math>x \ll y</math>, <math>y \ll z</math> implies <math>x \ll z</math>
* <math>\,x \prec y</math>, <math>\,y \prec z</math> implies <math>\,x \prec z</math>
and satisfy<ref name = "Penrose12"/>
* <math>x \ll y</math> implies <math>x \prec y</math> (this follows trivially from the definition)
* <math>x \ll y</math>, <math>y \prec z</math> implies <math>x \ll z</math>
* <math>x \prec y</math>, <math>y \ll z</math> implies <math>x \ll z</math>
 
== Causal structure ==
For a point <math>x</math> in the manifold <math>M</math> we define<ref name = "Penrose12"/>
* The '''chronological future''' of <math>x</math>, denoted <math>\,I^+(x)</math>, as the set of all points <math>y</math> in <math>M</math> such that <math>x</math> chronologically precedes <math>y</math>:
 
:<math>\,I^+(x) = \{ y \in M | x \ll y\}</math>
* The '''chronological past''' of <math>x</math>, denoted <math>\,I^-(x)</math>, as the set of all points <math>y</math> in <math>M</math> such that <math>y</math> chronologically precedes <math>x</math>:
 
:<math>\,I^-(x) = \{ y \in M | y \ll x\}</math>
 
We similarly define
* The '''causal future''' (also called the '''absolute future''') of <math>x</math>, denoted <math>\,J^+(x)</math>, as the set of all points <math>y</math> in <math>M</math> such that <math>x</math> causally precedes <math>y</math>:
 
:<math>\,J^+(x) = \{ y \in M | x \prec y\}</math>
* The '''causal past''' (also called the '''absolute past''') of <math>x</math>, denoted <math>\,J^-(x)</math>, as the set of all points <math>y</math> in <math>M</math> such that <math>y</math> causally precedes <math>x</math>:
 
:<math>\,J^-(x) = \{ y \in M | y \prec x\}</math>
 
Points contained in <math>\, I^+(x)</math>, for example, can be reached from <math>x</math> by a future-directed timelike curve.
The point <math>x</math> can be reached, for example, from points contained in <math>\,J^-(x)</math> by a future-directed non-spacelike curve.
 
As a simple example, in [[Minkowski spacetime]] the set <math>\,I^+(x)</math> is the [[interior (topology)|interior]] of the future [[light cone]] at <math>x</math>. The set <math>\,J^+(x)</math> is the full future light cone at <math>x</math>, including the cone itself.
 
These sets <math>\,I^+(x) ,I^-(x), J^+(x), J^-(x)</math>
defined for all <math>x</math> in <math>M</math>, are collectively called the '''causal structure''' of <math>M</math>.
 
For <math>S</math> a [[subset]] of <math>M</math> we define<ref name = "Penrose12"/>
 
:<math>I^\pm(S) = \bigcup_{x \in S} I^\pm(x) </math>
:<math>J^\pm(S) = \bigcup_{x \in S} J^\pm(x) </math>
 
For <math>S, T</math> two [[subset]]s of <math>M</math> we define
 
* The '''chronological future of <math>S</math> relative to <math>T</math>''', <math>I^+(S;T)</math>, is the chronological future of <math>S</math> considered as a submanifold of <math>T</math>. Note that this is quite a different concept from <math>I^+(S) \cap T</math> which gives the set of points in <math>T</math> which can be reached by future-directed timelike curves starting from <math>S</math>. In the first case the curves must lie in <math>S</math> in the second case they do not. See Hawking and Ellis.
 
* The '''causal future of <math>S</math> relative to <math>T</math>''', <math>J^+(S;T)</math>, is the causal future of <math>S</math> considered as a submanifold of <math>T</math>. Note that this is quite a different concept from <math>J^+(S) \cap T</math> which gives the set of points in <math>T</math> which can be reached by future-directed causal curves starting from <math>S</math>. In the first case the curves must lie in <math>S</math> in the second case they do not. See Hawking and Ellis.
 
* A '''future set''' is a set closed under chronological future.
* A '''past set''' is a set closed under chronological past.
 
* An '''indecomposable past set''' is a past set which isn't the union of two different open past proper subsets.
 
* <math>I^-(x)</math> is a '''proper indecomposable past set''' (PIP).
* A '''terminal indecomposable past set''' (TIP) is an IP which isn't a PIP.
 
* The future '''Cauchy development''' of <math>S</math>, <math>D^+ (S)</math> is the set of all points <math>x</math> for which every past directed inextendible causal curve through <math>x</math> intersects <math>S</math> at least once. Similarly for the past Cauchy development. The Cauchy development is the union of the future and past Cauchy developments. Cauchy developments are important for the study of [[determinism]].
 
* A subset <math>S \subset M</math> is '''achronal''' if there do not exist <math>q,r \in S</math> such that <math>r \in I^{+}(q)</math>, or equivalently, if <math>S</math> is disjoint from <math>I^{+}(S)</math>.
 
* A '''Cauchy surface''' is an closed achronal set whose Cauchy development is <math>M</math>.
 
* A metric is '''globally hyperbolic''' if it can be foliated by Cauchy surfaces.
 
* The '''chronology violating set''' is the set of points through which closed timelike curves pass.
 
* The '''causality violating set''' is the set of points through which closed causal curves pass.
 
* For a causal curve <math>\gamma</math>, the '''causal diamond''' is <math>J^+(\gamma) \cap J^-(\gamma)</math> (here we are using the looser definition of 'curve' whereon it is just a set of points). In words: the causal diamond of a particle's world-line <math>\gamma</math> is the set of all events that lie in both the past of some point in <math>\gamma</math> and the future of some point in <math>\gamma</math>.
 
=== Properties ===
 
See Penrose, p13.
 
* A point <math>x</math> is in <math>\,I^-(y)</math> if and only if <math>y</math> is in <math>\,I^+(x)</math>.
* <math>x \prec y \implies I^-(x) \subset I^-(y)</math>
* <math>x \prec y \implies I^+(y) \subset I^+(x)</math>
* <math>I^+[S] = I^+[I^+[S]] \subset J^+[S] = J^+[J^+[S]]</math>
* <math>I^-[S] = I^-[I^-[S]] \subset J^-[S] = J^-[J^-[S]]</math>
 
* The horismos is generated by null geodesic congruences.
 
[[Topology|Topological]] properties:
* <math>I^\pm(x)</math> is open for all points <math>x</math> in <math>M</math>.
* <math>I^\pm[S]</math> is open for all subsets <math>S \subset M</math>.
* <math>I^\pm[S] = I^\pm[\overline{S}]</math> for all subsets <math>S \subset M</math>. Here <math>\overline{S}</math> is the [[Closure (mathematics)|closure]] of a subset <math>S</math>.
* <math>J^\pm[S] \subset \overline{I^\pm[S]}</math>
 
== Conformal geometry ==
 
Two metrics <math>\,g</math> and <math>\hat{g}</math> are '''conformally related'''<ref>{{harvnb|Hawking|Ellis|1973|p=42}}</ref> if <math>\hat{g} = \Omega^2 g</math> for some real function <math>\Omega</math> called the '''conformal factor'''. (See [[conformal map#Riemannian geometry|conformal map]]).
 
Looking at the definitions of which tangent vectors are timelike, null and spacelike we see they remain unchanged if we use <math>\,g</math> or <math>\hat{g}.</math> As an example suppose <math>X</math> is a timelike tangent vector with respect to the <math>\,g</math> metric. This means that <math>\,g(X,X) > 0</math>. We then have that <math>\hat{g}(X,X) = \Omega^2 g(X,X) > 0</math> so <math>X</math> is a timelike tangent vector with respect to the <math>\hat{g}</math> too.
 
It follows from this that the causal structure of a Lorentzian manifold is unaffected by a [[conformal transformation]].
 
== See also ==
 
* [[Spacetime]]
* [[Lorentzian manifold]]
* [[Causality conditions]]
* [[Cauchy surface]]
* [[Globally hyperbolic manifold]]
* [[Closed timelike curve]]
* [[Penrose diagram]]
* [[Horismos]]
 
== Notes ==
<references/>
 
==References==
 
*{{citation | authorlink1=Stephen Hawking|first1=S.W.|last1=Hawking|authorlink2=George Francis Rayner Ellis|first2=G.F.R.|last2=Ellis| title=[[The Large Scale Structure of Space-Time]] | location=Cambridge | publisher=Cambridge University Press | year=1973 | isbn=0-521-20016-4}}
 
*{{citation | authorlink1=Stephen Hawking|first1=S.W.|last1=Hawking|authorlink2=Werner Israel|first2=W.|last2=Israel| title = General Relativity, an Einstein Centenary Survey| publisher = Cambridge University Press | year=1979 | isbn=0-521-22285-0}}
 
*{{citation | authorlink = Roger Penrose|first=R.|last=Penrose| title = Techniques of Differential Topology in Relativity| publisher = SIAM | year = 1972 | isbn=0898710057}}
 
==Further reading==
<div class="references-small">
*[[Gary Gibbons|G. W. Gibbons]], S. N. Solodukhin; ''The Geometry of Small Causal Diamonds'' [[arXiv:hep-th/0703098]] (Causal intervals)
 
*[[Stephen Hawking|S.W. Hawking]], A.R. King, P.J. McCarthy; ''[http://link.aip.org/link/?JMAPAQ/17/174/1 A new topology for curved space–time which incorporates the causal, differential, and conformal structures]''; J. Math. Phys. 17 2:174-181 (1976);  (Geometry, [[Causal Structure]])
 
*A.V. Levichev; ''Prescribing the conformal geometry of a lorentz manifold by means of its causal structure''; Soviet Math. Dokl. 35:452-455, (1987); (Geometry, [[Causal Structure]])
 
*[[David Malament|D. Malament]]; ''[http://link.aip.org/link/?JMAPAQ/18/1399/1 The class of continuous timelike curves determines the topology of spacetime]''; J. Math. Phys. 18 7:1399-1404 (1977);  (Geometry, [[Causal Structure]])
 
*[[Alfred Robb|A.A. Robb]] ; ''[http://www.archive.org/details/theoryoftimespac00robbrich A theory of time and space]''; Cambridge University Press, 1914; (Geometry, [[Causal Structure]])
 
*[[Alfred Robb|A.A. Robb]] ; ''[http://www.archive.org/details/relationsoftime00robbuoft The absolute relations of time and space]''; Cambridge University Press, 1921; (Geometry, [[Causal Structure]])
 
*[[Alfred Robb|A.A. Robb]] ; ''[http://www.archive.org/details/geometryoftimean032218mbp Geometry of Time and Space]''; Cambridge University Press, 1936; (Geometry, [[Causal Structure]])
 
*[[Rafael Sorkin|R.D. Sorkin]], E. Woolgar; ''A Causal Order for Spacetimes with C^0 Lorentzian Metrics: Proof of Compactness of the Space of Causal Curves''; Classical & Quantum Gravity 13: 1971-1994 (1996); [[arXiv:gr-qc/9508018]] ([[Causal Structure]])
</div>
 
== External links ==
* [http://demonstrations.wolfram.com/TuringMachineCausalNetworks/  Turing Machine Causal Networks] by Enrique Zeleny, the [[Wolfram Demonstrations Project]]
* {{MathWorld |title=Causal Network |urlname=CausalNetwork}}
 
[[Category:Lorentzian manifolds]]
[[Category:Theory of relativity]]
[[Category:General relativity]]
[[Category:Theoretical physics]]

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In mathematical physics, the causal structure of a Lorentzian manifold describes the causal relationships between points in the manifold.

Introduction

In modern physics (especially general relativity) spacetime is represented by a Lorentzian manifold. The causal relations between points in the manifold are interpreted as describing which events in spacetime can influence which other events.

Minkowski spacetime is a simple example of a Lorentzian manifold. The causal relationships between points in Minkowski spacetime take a particularly simple form since the space is flat. See Causal structure of Minkowski spacetime for more information.

The causal structure of an arbitrary (possibly curved) Lorentzian manifold is made more complicated by the presence of curvature. Discussions of the causal structure for such manifolds must be phrased in terms of smooth curves joining pairs of points. Conditions on the tangent vectors of the curves then define the causal relationships.

Tangent vectors

If is a Lorentzian manifold (for metric on manifold ) then the tangent vectors at each point in the manifold can be classed into three different types. A tangent vector is

(Here we use the metric signature). A tangent vector is called "non-spacelike" if it is null or timelike.

These names come from the simpler case of Minkowski spacetime (see Causal structure of Minkowski spacetime).

Time-orientability

At each point in the timelike tangent vectors in the point's tangent space can be divided into two classes. To do this we first define an equivalence relation on pairs of timelike tangent vectors.

If and are two timelike tangent vectors at a point we say that and are equivalent (written ) if .

There are then two equivalence classes which between them contain all timelike tangent vectors at the point. We can (arbitrarily) call one of these equivalence classes "future-directed" and call the other "past-directed". Physically this designation of the two classes of future- and past-directed timelike vectors corresponds to a choice of an arrow of time at the point. The future- and past-directed designations can be extended to null vectors at a point by continuity.

A Lorentzian manifold is time-orientable[1] if a continuous designation of future-directed and past-directed for non-spacelike vectors can be made over the entire manifold.

Curves

A path in is a continuous map where is a nondegenerate interval (i.e., a connected set containing more than one point) in . A smooth path has differentiable an appropriate number of times (typically ), and a regular path has nonvanishing derivative.

A curve in is the image of a path or, more properly, an equivalence class of path-images related by re-parametrisation, i.e. homeomorphisms or diffeomorphisms of . When is time-orientable, the curve is oriented if the parameter change is required to be monotonic.

Smooth regular curves (or paths) in can be classified depending on their tangent vectors. Such a curve is

  • chronological (or timelike) if the tangent vector is timelike at all points in the curve.
  • null if the tangent vector is null at all points in the curve.
  • spacelike if the tangent vector is spacelike at all points in the curve.
  • causal (or non-spacelike) if the tangent vector is timelike or null at all points in the curve.

The requirements of regularity and nondegeneracy of ensure that closed causal curves (such as those consisting of a single point) are not automatically admitted by all spacetimes.

If the manifold is time-orientable then the non-spacelike curves can further be classified depending on their orientation with respect to time.

A chronological, null or causal curve in is

  • future-directed if, for every point in the curve, the tangent vector is future-directed.
  • past-directed if, for every point in the curve, the tangent vector is past-directed.

These definitions only apply to causal (chronological or null) curves because only timelike or null tangent vectors can be assigned an orientation with respect to time.

  • A closed timelike curve is a closed curve which is everywhere future-directed timelike (or everywhere past-directed timelike).
  • A closed null curve is a closed curve which is everywhere future-directed null (or everywhere past-directed null).
  • The holonomy of the ratio of the rate of change of the affine parameter around a closed null geodesic is the redshift factor.

Causal relations

There are two types of causal relations between points and in the manifold .

These relations are transitive:[3]

and satisfy[3]

Causal structure

For a point in the manifold we define[3]

We similarly define

Points contained in , for example, can be reached from by a future-directed timelike curve. The point can be reached, for example, from points contained in by a future-directed non-spacelike curve.

As a simple example, in Minkowski spacetime the set is the interior of the future light cone at . The set is the full future light cone at , including the cone itself.

These sets defined for all in , are collectively called the causal structure of .

For a subset of we define[3]

For two subsets of we define

  • A future set is a set closed under chronological future.
  • A past set is a set closed under chronological past.
  • An indecomposable past set is a past set which isn't the union of two different open past proper subsets.
  • A metric is globally hyperbolic if it can be foliated by Cauchy surfaces.
  • The chronology violating set is the set of points through which closed timelike curves pass.
  • The causality violating set is the set of points through which closed causal curves pass.

Properties

See Penrose, p13.

  • The horismos is generated by null geodesic congruences.

Topological properties:

Conformal geometry

Two metrics and are conformally related[4] if for some real function called the conformal factor. (See conformal map).

Looking at the definitions of which tangent vectors are timelike, null and spacelike we see they remain unchanged if we use or As an example suppose is a timelike tangent vector with respect to the metric. This means that . We then have that so is a timelike tangent vector with respect to the too.

It follows from this that the causal structure of a Lorentzian manifold is unaffected by a conformal transformation.

See also

Notes

References

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    Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region

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    To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010
  • Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.

    Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.

    In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.

    Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region

    Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.

    15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.

    To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010
  • Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.

    Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.

    In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.

    Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region

    Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.

    15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.

    To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010

Further reading

  • A.V. Levichev; Prescribing the conformal geometry of a lorentz manifold by means of its causal structure; Soviet Math. Dokl. 35:452-455, (1987); (Geometry, Causal Structure)

External links

  • Turing Machine Causal Networks by Enrique Zeleny, the Wolfram Demonstrations Project


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