text stringlengths 100 500k | subset stringclasses 4
values |
|---|---|
There are 49 balls and if your choice of 6 numbers matches 5 winning balls plus the bonus number (a 7th ball drawn) then this generally wins around £100,000 and has a probability 1 in 2,330,636.
The new 'Health Lottery' has a poor payout to the punters of around 33p in the pound, but 5 numbers out of 50 would win 'up t... | CommonCrawl |
Real Algebraic and Analytic Geometry.
Related manuscripts and search engines for mathematical preprints.
Vincent Astier and Thomas Unger: Positive cones on algebras with involution.
Vincent Astier, Thomas Unger: Signatures of hermitian forms, positivity, and an answer to a question of Procesi and Schacher.
Patrick Spei... | CommonCrawl |
where for a surface embedded in $\mathbb R^3 $ for shallow shell geometry we took $z=f(x,y)=w $ from Mongé form and neglected squares of first order partial derivatives $ (p ,q) $ in its denominator.The standard differential relation can be linked to classical large deformation theory of deformations of Plates and Shel... | CommonCrawl |
All currently known construction methods of smooth compact $\mathrm G_2$-manifolds have been tied to certain singular $\mathrm G_2$-spaces, which in Joyce's original construction are $\mathrm G_2$-orbifolds and in Kovalev's twisted connected sum construction are complete G2-manifolds with cylindrical ends. By a slight ... | CommonCrawl |
I know how to solve a Rubik $4\times4\times4$ or $5\times5\times5$ or bigger, but I have problem with a specific algorithm: the parity error.
What's the shortest parity algorithm for $n\times n\times n$, or is there a really easy way to memorize parity?
Unfortunately, there's not an easy way to spot or correct parity e... | CommonCrawl |
What are some good canned classifiers for high-dimensional data with probablistic labels, besides neural nets?
I've got a classification problem where my labels are $N\times4$ matrices of probabilities of class membership, and I've got about 1800 covariates. The covariates are mostly granular, in the sense that an addi... | CommonCrawl |
The physiological sleep inducers are adenosine and the hormone melatonin. Melatonin is secreted by the epithalamus gland. It's concentration is high in the dark and it induces sleep by inhibiting the RAS.
When the brain is performing, it uses high level of ATP, which generates the adenosine. When significant amount of ... | CommonCrawl |
I have 2 questions regarding the naming of secondary structure elements ($\alpha$-helix and $\beta$-sheets), like helix C or sheet 2, which are often used in publications.
Who assigns the characters and numbers to the helices and sheets? The authors of the paper where the structure is published (considering possible ho... | CommonCrawl |
A condition on a region of Euclidean space expressing some non-flatness property. An open set $G\subset E^n$ satisfies the weak cone condition if $x+V(e(x),H)\subset G$ for all $x\in G$, where $V(e(x),H)$ is a right circular cone with vertex at the origin of fixed opening $\epsilon$ and height $H$, $0\leq H\leq\infty$,... | CommonCrawl |
Romain Pétrides (Paris Diderot University) will speak in the geometry seminar on Tuesday 19 June, at 1.30pm in the Salle de Profs. Romain's title is Min-Max construction for free boundary minimal disks and his abstract is below.
We will discuss existence of minimal disks into a Riemannian manifold having a boundary lyi... | CommonCrawl |
Using julia -L startupfile.jl, rather than machinefiles for starting workers.
These are some terms that get thrown around a lot by julia programmers. This is a brief writeup of a few of them.
This is a blog post about about dispatch. Mostly, single dispatch, though it trivially generalises to multiple dispatch, because... | CommonCrawl |
Results concerning the existence of solutions of multipoint boundary value problems are given. The results are based on a topological transversality method and rely on a priori bounds on solutions. Applications are made to conjugate type and focal type boundary value problems; the third order, 3-point boundary value pr... | CommonCrawl |
In many introductory courses to quantum mechanics, we see $\delta$-functions all over the place. For example when expressing an arbitrary wave function $\psi(x)$ in the basis of eigenfunctions of the position operator $\hat x$ as $$ \psi(x) = \int\mathrm d\xi\, \delta(x-\xi)\, \psi(\xi). $$ In bra-ket notation this cor... | CommonCrawl |
I am a bit confused about the definition of weak del pezzo surface. Can someone give an example that what kind of weak del pezzo surface is not a del pezzo surface?
A surface $S$ is del Pezzo if $-K_S$ is ample. It is weak del Pezzo if $-K_S$ is nef and big.
To get examples of (true) weak del Pezzos, remember that a de... | CommonCrawl |
Abdallah Ben Abdallah, Farhat Shel. Exponential stability of a general network of 1-d thermoelastic rods. Mathematical Control & Related Fields, 2012, 2(1): 1-16. doi: 10.3934\/mcrf.2012.2.1.
Kangsheng Liu, Xu Liu, Bopeng Rao. Eventual regularity of a wave equation with boundary dissipation. Mathematical Control & Rela... | CommonCrawl |
"... which induces an exact sequence in homotopy $$\ldots\pi_2(S^1)\to\pi_2(S^3)\to\pi_2(S^2)\to\pi_1(S^1)\to\pi_1(S^3)\to\pi_1(S^1)\ldots$$ from which the higher homotopy groups of spheres could be computed ..."
Now I know exact sequences, some algebraic topology and how continuous maps induce maps on homology and how... | CommonCrawl |
Abstract: Wreath products of finite groups have permutation representations that are constructed from the permutation representations of their constituents. One can envision these in a metaphoric sense in which a rope is made from a bundle of threads. In this way, subgroups and quotients are easily visualized. The gene... | CommonCrawl |
Example 1: Any collection $\mathbf A$ of binary relations on a set $X$ such that $\mathbf A$ is closed under union, intersection and composition. Example 1: Any collection $\mathbf A$ of binary relations on a set $X$ such that $\mathbf A$ is closed under union, intersection and composition.
- Andreka 1991 AU proves tha... | CommonCrawl |
BellInequalityMaxQubits: Approximates the optimal value of a Bell inequality in qubit (i.e., 2-dimensional quantum) settings.
NonlocalGameValue: Computes the maximum value of a nonlocal game in a classical, quantum, or no-signalling setting.
BellInequalityMax: Bug fix when computing the classical value of a Bell inequa... | CommonCrawl |
tl;dr We benchmark dask on an out-of-core dot product. We also compare and motivate the use of an optimized BLAS.
Disclaimer: This post is on experimental buggy code. This is not ready for public use.
We now give performance numbers on out-of-core matrix-matrix multiplication.
Dense matrix-matrix multiplication is comp... | CommonCrawl |
Abstract: We describe a method that is used to reduce, significantly, the number of CP violating complex phases in the Yukawa parameters. With this Reduction of Complex Phases (RCP) we obtain only one CP violating complex phase in the case where the neutrinos have an (effective) $3\times 3$ Majorana mass matrix. For th... | CommonCrawl |
In the link above it is discussed that the interesting feature of Jeffreys prior is that, when reparameterizing the model, the resulting posterior distribution gives posterior probabilities that obey the restrictions imposed by the transformation. Say, as discussed there, when moving from the success probability $\thet... | CommonCrawl |
Distributed Denial-of-Service (DDoS) attacks continue to be a major threat in the Internet today. DDoS attacks overwhelm target services with requests or other traffic, causing requests from legitimate users to be shut out. A common defense against DDoS is to replicate the service in multiple physical locations or site... | CommonCrawl |
The rings considered in this article are commutative with identity. This article is motivated by the work on comaximal graphs of rings. In this article, with any ring $R$, we associate an undirected graph denoted by $G(R)$, whose vertex set is the set of all elements of $R$ and distinct vertices $x,y$ are joined by an ... | CommonCrawl |
Dario Pighin is a PhD Student at Universidad Autónoma de Madrid (UAM). He earned both the Bachelor's Degree and the Master's Degree in Mathematics at the University of Rome Tor Vergata (Rome 2). Currently, he is studying for his PhD in Control Theory, under the joint supervision of professor Enrique Zuazua.
Master degr... | CommonCrawl |
Posted on 27/10/2018, in Machine Learning.
This note was first taken when I learnt the machine learning course on Coursera.
Lectures in this week: Lecture 13, Lecture 14.
error This note of Alex Holehouse is also very useful (need to be used alongside with my note).
settings_backup_restore Go back to Week 7.
This is th... | CommonCrawl |
John has 77 boxes each having dimensions 3x3x1. Is it possible for John to build one big box with dimensions 7x9x11?
I'm leaning towards no, but I would like others opinion.
The answer is no; John can't even fill up the topmost $7\times 11\times 1$ slice of the $7\times 11\times 9$ box. Consider just the top $7\times 1... | CommonCrawl |
How do we incorporate new information into a Dirichlet prior distribution?
My problem is this: I have an ensemble of predictors that each produces a distribution over a set of classes.
What I would like to do is to first have a non-informative prior about how this label distribution looks like, and then update that pri... | CommonCrawl |
Elections and statistics: the case of "United Russia", 2009-2012Apr 02 2012The election statistics analysis does not confirm the assumption of correct ballot counting (a survey).
Elections and statistics: the case of "United Russia", 2009-2018Apr 02 2012Jun 23 2018The election statistics analysis does not confirm the a... | CommonCrawl |
Given that $ a\; $and $\;b $ are integers and $ a\;+a^2\;b^3 $ is odd, which one of the following statements is correct ?
From the time the front of a train enters a platform, it takes 25 seconds for the back of the train to leave the platform, while travelling at a constant speed of 54 km/h. At the same speed, it take... | CommonCrawl |
Relationship between logical axioms and tautologies?
"Logical axioms are formulas that are satisfied by every assignment of values. Usually one takes as logical axioms at least some minimal set of tautologies that is sufficient for proving all tautologies in the language; in the case of predicate logic more logical axi... | CommonCrawl |
I'd hope the title is self explanatory. In Kaggle, most winners use stacking with sometimes hundreds of base models, to squeeze a few extra % of MSE, accuracy... In general, in your experience, how important is fancy modelling such as stacking vs simply collecting more data and more features for the data?
By way of bac... | CommonCrawl |
$\star$ Argue that for any constant $0 < \alpha \le 1/2$, the probability is approximately $1 - 2\alpha$ that on a random input array, PARTITION produces a split more balanced than $1 - \alpha$ to $\alpha$.
In order to produce a worse split than $\alpha$ to $1 - \alpha$, PARTITION must pick a pivot that will be either ... | CommonCrawl |
In this talk, we consider a time harmonic acoustic problem in a locally perturbed waveguide. We are interested in a situation where an observer generates incident propagative waves from $-\infty$ and measures the resulting scattered field at $-\infty$ and/or $+\infty$. We explain how to construct perturbations of the w... | CommonCrawl |
Lemma 15.28.6. Let $R$ be a ring. Let $f_1, \ldots , f_ r \in R$ be a sequence. Multiplication by $f_ i$ on $K_\bullet (f_\bullet )$ is homotopic to zero, and in particular the cohomology modules $H_ i(K_\bullet (f_\bullet ))$ are annihilated by the ideal $(f_1, \ldots , f_ r)$.
In order to prevent bots from posting co... | CommonCrawl |
There is a large hotel, and $n$ customers will arrive soon. Each customer wants to have a single room.
You know each customer's arrival and departure day. Two customers can stay in the same room if the departure day of the first customer is earlier than the arrival day of the second customer.
What is the minimum number... | CommonCrawl |
I'm a postdoc of mathematics at the University of Jyväskylä, Finland. My research is focused on inverse problems, and the main tools are differential geometry, functional analysis and PDEs. One of my long time hobbies is Latin language. See my homepage for more information.
120 Updating the Hot Network Questions List -... | CommonCrawl |
Previously I've posted about the lambda calculus and Church numbers. We'd shown how we can encode numbers as functions using the Church encoding, but we'd not really shown how we could do anything with those numbers.
As we still need the parentheses to make sure that the $f$ and $x$ get bundled together. We'll need thi... | CommonCrawl |
In this theoretical contribution, we chose to use an indenter having a spherical geometrical form, which we used to model the surfaces mixture to separate the contributions of substrate and film in the composite covered material hardness. We have considered the coefficients $\alpha$, $\beta$ of the model as ratios of t... | CommonCrawl |
BOOST2016 is the eighth of a series of successful joint theory/experiment workshops that bring together the world's leading experts from theory and LHC experiments to discuss the latest progress and develop new approaches on the reconstruction of and use of boosted decay topologies in order to search for new physics. T... | CommonCrawl |
Fact: Start with $V$ a subspace of $\mathbb R^n$. Take the set of all supports of vectors in $V$. Throw out $\emptyset$. You now have the dependent sets of some matroid.
Not sure you believe me? Or just want to get your hands on the independent sets? (If you tell people that you have a matroid, they always ask you for ... | CommonCrawl |
You can navigate this wiki by using the sidebar which lists the main entries (examples, problems,…) and gathers the "tags" or keywords. You can also use the "Table of Content" in the top bar.
A typical orbit for: $z\mapsto\beta z \mod \mathbb Z^2$ for $|\beta|>1$.
This is a place for (references to) uses of and results... | CommonCrawl |
Abstract: Let $p(t)$ be an admissible Hilbert polynomial in $\PP^n$ of degree $d$. The Hilbert scheme $\hilb^n_p(t)$ can be realized as a closed subscheme of a suitable Grassmannian $ \mathbb G$, hence it could be globally defined by homogeneous equations in the Plucker coordinates of $ \mathbb G$ and covered by open s... | CommonCrawl |
Cavity optomechanics provides a platform for exquisitely controlling coherent interactions between photons and mesoscopic mechanical excitations. Cavity optomechanics has recently been used to demonstrate phenomena such as laser cooling, optomechanically induced transparency, and coherent wavelength conversion. These e... | CommonCrawl |
"If the axiom of constructibility holds then there is a subset of the product of the Baire space with itself which is $\Delta^1_2$ and is the graph of a well ordering of the Baire space. If the axiom holds then there is also a $\Delta^1_2$ well ordering of Cantor space."
Can someone (give here or point me to) a (sketch... | CommonCrawl |
1 . What should come in place of question mark (?) in the following questions?
2 . What should come in place of question mark (?) in the following questions?
3 . What should come in place of question mark (?) in the following questions?
4 . What should come in place of question mark (?) in the following questions?
5 . ... | CommonCrawl |
Manage passwords, documents and other confidential data from one source!
Password Depot is a powerful and very user-friendly password manager for PC which helps to organize all of your passwords – but also, for instance, information from your credit cards or software licenses. The software provides security for your pa... | CommonCrawl |
27/03/2012�� The critical value is the value from the distribution of the test for which P(X>X critical value) = alpha, where X is the observed test statistic and X critical value is the critical value for the test.... Practice finding the critical value z* for some given confidence level. If you're seeing this message... | CommonCrawl |
where $\theta, \alpha$ and $\sigma$ are time-dependent.
First, I treat $\alpha_t$ as the mean of my process (~$\mu_t$). I am estimating and forecasting $\mu_t$ using the Local Linear Trend State Space model and the Kalman Filter.
Then, comes my problem. Since $\theta$ is changing over time I cannot estimate it. If it w... | CommonCrawl |
A tautology is a statement which is always true, independently of any relevant circumstances that could theoretically influence its truth value.
if $p$ is true then $p$ is true.
An example of a "relevant circumstance" here is the truth value of $p$.
The archetypal tautology is symbolised by $\top$, and referred to as T... | CommonCrawl |
Abstract: A class of solutions to a Darboux system in $\mathbb R^3$ is introduced that satisfy the factorization condition for an auxiliary second-order linear problem. It is shown that this reduction provides the (local) solvability of the Darboux system, and an explicit solution is given to this problem for two types... | CommonCrawl |
This is more a question about singular, since that is what Sage uses to computer the Groebner Basis. In Singular, you can use option(prot) and then, upon using the groebner function of your choice, you will see verbose output. From the Singular manual, we are told that when "s" is printed in the verbose output, a new e... | CommonCrawl |
Why are temperatures generally hotter in the Middle East than in Europe?
How come the average temperature in the middle east (Israel, Saudi Arabia, Sudan or lower) is always so much significantly higher than in Europe (say Germany, England etc.)?
I know that the sun rays pass a greater distance to Europe than the middl... | CommonCrawl |
21 Why, in terms of quantum groups, does the knot determinant appear as an evaluation of both the Jones and Alexander polynomials?
13 How unique are extensions of TQFTs to lower dimension?
11 Is there a reasonable definition of TQFTs for n-cobordisms with connected inputs/outputs?
10 When were bordered Heegaard Floer h... | CommonCrawl |
Consider a Directed Acyclic Graph in which every node has a value and a cost and edges do not have any weight. I need to find a path containing nodes such that sum of values of these nodes is maximized, but sum of cost over all these nodes must be at most C.
I am thinking of some modification of Dijkstra's algorithm. A... | CommonCrawl |
Let $G$ be a reductive algebraic group over $\mathbb R$ and $K$ a maximal compact subgroup. Then we refer to the conjugacy class in $G$ of some $k \in K$ as an elliptic conjugacy class.
Question: Can one characterizes those conjugacy classes in $G$ which contain an elliptic conjugacy class in their closure?
For g in G,... | CommonCrawl |
Eve loves puzzles. She recently bought a new one that has proven to be quite difficult. The puzzle is made of a rectangular grid with $R$ rows and $C$ columns. Some cells may be marked with a dot, while the other cells are empty. Four types of pieces come with the puzzle, and there are $R \times C$ units of each type.
... | CommonCrawl |
Some notes on Euler productsDec 21 2014We focus on a well-known convergence phenomenon, the fact that the $\zeta$ zeros are the universal singularities of certain Euler products.
Piecewise constant local martingales with bounded numbers of jumpsDec 23 2016A piecewise constant local martingale $M$ with boundedly many ju... | CommonCrawl |
What does the broken vertical bar ¦ mean?
If $\mathbf a\cdot \mathbf b = \mathbf a\cdot \mathbf c$ where $\mathbf a ¦ \mathbf 0¦\mathbf b$, what conclusion(s) can be made?
Any ideas what the symbol means?
Browse other questions tagged notation vectors or ask your own question.
what does the inverse membership symbol me... | CommonCrawl |
Given an $n \times n$ grid with unit grid cells, and one point from the interior of each cell, what is are best possible lower and upper bounds for lengths of minimum spanning trees? The lower bound version of problem seems generate trees that are related to the Euclidean Steiner Tree Problem.
If $n < 4$ the problem is... | CommonCrawl |
In a ring, how do we prove that a * 0 = 0?
In a ring, I was trying to prove that for all $a$, $a0 = 0$.
But I found that this depended on a lemma, that is, for all $a$ and $b$, $a(-b) = -ab = (-a)b$.
I am wondering how to prove these directly from the definition of a ring.
$a0 = a(0+0)= a0 + a0$, property of $0$ and di... | CommonCrawl |
Abstract: The HERAPDF1.0 PDF set, which was an NLO QCD analysis based on H1 and ZEUS combined inclusive cross section data from HERA-I, has been updated to HERAPDF1.5 by including preliminary inclusive cross section data from HERA-II running. Studies have also been made by adding various other HERA data sets: combined ... | CommonCrawl |
Which functions of one variable are derivatives ?
This is motivated by this recent MO question.
Is there a complete characterization of those functions $f:(a,b)\rightarrow\mathbb R$ that are pointwise derivative of some everywhere differentiable function $g:(a,b)\rightarrow\mathbb R$ ?
Of course, continuity is a suffic... | CommonCrawl |
I'm not familiar with interval solutions for absolute equations.
How to solve for this interval?
The first thing to do is to notice that if $x$ is large and positive, then $|3-x|$ is the same as $x-3$, so the equation becomes $$ (x-3)+4x = 5(x+2) -13 \\ 5x-3 = 5x -3 $$ and so any time $x$ is that large, the equation is... | CommonCrawl |
Lemma 15.44.12. Let $A$ be a ring. Let $B$ be a filtered colimit of étale $A$-algebras. Let $\mathfrak p$ be a prime of $A$. If $B$ is Noetherian, then there are finitely many primes $\mathfrak q_1, \ldots , \mathfrak q_ r$ lying over $\mathfrak p$, we have $B \otimes _ A \kappa (\mathfrak p) = \prod \kappa (\mathfrak ... | CommonCrawl |
Imagine you have a plane, flat surface with a square grid drawn on it. You have a standard cubic die which is placed flat on the surface. Its length is the same as the length of side of each grid square. The only way to move the die to an adjacent square is by tipping the die into the square. So obviously the die canno... | CommonCrawl |
The interaction of turbulent wakes with one another and with the adjacent fluid directly impacts the generation of electricity in wind turbine arrays. Computational modeling is well suited to the repeated iterations of data generation that may be required to inform understanding of the function of wind farms as well as... | CommonCrawl |
In this, the third of these articles on Whole Number Dynamics , we shall complete the solution to the problem started in the first article . The later articles in this series will deal with other problems with the same theme.
Let us remind ourselves of the problem. Starting with any whole number between 1 and 999 inclu... | CommonCrawl |
Is the wave-particle duality a real duality?
How do I construct the $SU(2)$ representation of the Lorentz Group using $SU(2)\times SU(2)\sim SO(3,1)$ ?
Do virtual particles actually physically exist?
What is more fundamental, fields or particles?
What is a complete book for introductory quantum field theory?
Why path i... | CommonCrawl |
We prove a result about the existence of certain `sums-of-squares' formulas over a field $F$. A classical theorem uses topological $K$-theory to show that if such a formula exists over $\mathbb R$, then certain powers of $2$ must divide certain binomial coefficients. In this paper we use algebraic $K$-theory to extend ... | CommonCrawl |
A field line is a locus that is defined by a vector field and a starting location within the field. Field lines are useful for visualizing vector fields, which are otherwise hard to depict.... The answer depends on whether you want to A) draw magnetic field lines conceptually or B) draw actually magnetic field originat... | CommonCrawl |
The Price Rate of Change (ROC) is a momentum-based technical indicator that measures the percentage change in price between the current price and the price a certain number of periods ago. The ROC indicator is plotted against zero, with the indicator moving upwards into positive territory if price changes are to the up... | CommonCrawl |
A message may be accompanied with a digital signature, a MAC or a message hash, as a proof of some kind. Which assurances does each primitive provide to the recipient? What kind of keys are needed?
Is there an example of two known strings which have the same MD5 hash value (representing a so-called "MD5 collision")?
Ha... | CommonCrawl |
Now a colleger, wanted to be a physicist, but now also a mathematician. Hee hee.
Meaning and usage of complex number functor and monad?
Why is the Major-Minor Scale unused?
Is mfix for Maybe impossible to be nontrivially total?
Is there a name for, or notable structure that uses, weird "distributive laws" such as $a\ti... | CommonCrawl |
Ramesh was born on 28 February of a year. If in that year Republic Day fell on Sunday, then on which day was Ramesh born ?
A person puts some money on bet and loses. He again puts double the amount on bet and loses again. Again he puts on bet double the amount of the previous bet and wins double the amount from this be... | CommonCrawl |
Po semináři bude s profesorem Shorem diskuse o jeho práci jednoho z vedoucích redaktorů časopisu Astronomy and Astrophysics.
A cosmic string modeled by an abelian Higgs vortex is studied in the rotating black hole background of the Kerr geometry. It is shown that such a system displays much richer phenomenology than it... | CommonCrawl |
This is actually an exercise in Landau-Lifshitz's book. Their solution goes as follows.
After we have found a frame of reference where $\mathbf E$ and $\mathbf B$ are parallel (let's call the common direction $\mathbf n$), every other frame of reference obtained by boosting along $\mathbf n$ is such a frame of referenc... | CommonCrawl |
What are the sub $C^*$-algebras of $C(X,M_n)$?
Let $X$ be a locally compact Hausdorff topological space, denote by $M_n$ the $C^*$-algebra of complex $n\times n$ matrices, by $C_0(X,M_n)$ the $C^*$-algebra of continuous functions on $X$ with values in $M_n$ vanishing at infinity, and by $C_b(X,M_n)$ the $C^*$-algebra o... | CommonCrawl |
Since the code was written during work hours, it was obviously a huge waste of company resources. To prevent similar occurrences in the future, we must minimize the waste of worked hours. And since it is common knowledge that a shorter program is faster to write, we must golf this code to be as short as possible!
A sin... | CommonCrawl |
Format: TextI edited [[stable (infinity,1)-category]] a bit: * rephrased the intro part, trying to make it more forcefully to the point (not claiming to have found the optimum, though) * added a dedicated section <a href="http://ncatlab.org/nlab/show/stable+(infinity%2C1)-category#the_homotopy_category_of_a_stable_cate... | CommonCrawl |
Abstract: We construct an approximate expression for the total cross section for the production of a heavy quark-antiquark pair in hadronic collisions at next-to-next-to-next-to-leading order (N$^3$LO) in $\alpha_s$. We use a technique which exploits the analyticity of the Mellin space cross section, and the informatio... | CommonCrawl |
"How do I show that a two-qubit state is an entangled state?" includes an answer which references the Peres–Horodecki criterion. This works for $2\times 2$ and $2\times3$ dimensional cases; however, in higher dimensions, it is "inconclusive." It is suggested to supplement with more advanced tests, such as those based o... | CommonCrawl |
Concentration is a not so popular 2 player card game of both skill and luck. The standard Concentration game is played with one or two 52-card decks, however, for the sake of the problem, we will look at a variation of Concentration.
A card is represented by a single integer. Two cards $i$, $j$ are considered "similar"... | CommonCrawl |
There exists a 9x9 grid with the cells in one single row numbered 1-9 in order. The cells in the other 8 rows are initially empty.
Note: The cells initially containing numbers can be in any one row; not necessarily the first.
The columns from left to right are numbered $1-9$ (as with the top row).
Firstly, $B9$ must be... | CommonCrawl |
math | God, Your Book Is Great !!
In this post, I plan to discuss about two very simple inequalities – Markov and Chebyshev. These are topics that are covered in any elementary probability course. In this post, I plan to give some intuitive explanation about them and also try to show them in different perspectives. Als... | CommonCrawl |
Many people find it hard to come up with a story problem that represents fraction division (including many math teachers, engineers, and mathematicians). Why is this hard to do? For many people, their schema for dividing fractions consists almost entirely of the "invert and multiply" rule. But there is much more to thi... | CommonCrawl |
You are planning to create a map of an RPG. This map is represented by a grid whose size is $H \times W$. Each cell in this grid is either '@', '*', '#', or '.'. The meanings of the symbols are as follows.
'@': The start cell. The story should start from this cell.
'*': A city cell. The story goes through or ends with ... | CommonCrawl |
1) How do we make sense of $X(f)$ with $X$ a vector field on $M$ and $f$ a smooth function on $M$?
2) How do we make sense of $Xg(Y,Z)$ where $g$ is a riemanian metric and $X,Y,Z$ vector fields.
To get this answered, the short answer to both questions is yes. A vector field $X$ is a section of the tangent bundle $TM$, ... | CommonCrawl |
Let $S$ be a surface. Is it true that if $S$ is covered by the hyperbolic plane (or a subset thereof) then it admits a Riemannian metric of constant negative curvature? How does the metric (or multiple metrics) arise?
Is the converse true? Again, how do we construct the covering(s)?
Relevant references would be much ap... | CommonCrawl |
Lets say I have two stocks x and y and their corresponding stock price p(x) and p(y). consider HR as hedge ratio. Then we can calculate the spread using this equation.
from this step what rationale should we use for buying and selling pairs?
Pairs trading works for two highly correlated stocks. We then sell the costlie... | CommonCrawl |
Is a square zero matrix positive semidefinite?
Does the fact that a square zero matrix contains non-negative eigenvalues (zeros) make it proper to say it is positive semidefinite?
The $n \times n$ zero matrix is positive semidefinite and negative semidefinite.
"When in doubt, go back to the basic definitions"! The defi... | CommonCrawl |
Right-skewed distribution with mean equals to mode?
Is it possible to have a right-skewed distribution with mean equal to mode? If so, could you give me some example?
Easy examples come from binomial distributions -- which can hardly be dismissed as pathological or as bizarre counter-examples constructed ad hoc. Here i... | CommonCrawl |
$\star$ Consider an open-address hash table with a load factor $\alpha$. Find the nonzero value $\alhpa$ for which the expected number of probes in an unsuccessful search equals twice the expected number of probes in a successful search. Use the upper bounds given by Theorems 11.6 and 11.8 for there expected number of ... | CommonCrawl |
Conference: The 35th International Colloquium on Automata, Languages and Programming (ICALP 2008).
Abstract: Given query access to a set of points in a metric space, we wish to quickly check if it has a specific property. More precisely, we wish to distinguish sets of points that have the property from those that need ... | CommonCrawl |
In QFT, the LSZ formula can be used to calculate S-matrix elements from time ordered products of fields (say $\phi)$), which gives the probability for a system to evolve from an initial state at asymptotic time consisiting of free particles to another asymptotic state consisting of other free particles. The only thing ... | CommonCrawl |
The following is a lightweight tutorial for loop invariant proofs. It assumes that you have heard about these proofs, but don't yet know what to do with them and how to do them.
Loop invariant proofs might seem scary at first, in particular if you are not used to writing mathematical proofs. But they shouldn't be: when... | CommonCrawl |
When an aircraft stalls, do all or most lift forces abruptly disappear or is this transition continuous? Will the aircraft drop from the sky like a brick or can this (losing lift and altitude) happen so gradually that it will be entirely unnoticed from the crew and passengers?
If lift abruptly disappears when entering ... | CommonCrawl |
Though once I am made, I am blind.
By makers as well as the made.
Explaining why I might have swayed.
For my classic is ever so white.
But at first kill the guest on the right.
But count only half of the numeral.
And the answer is there, not a funeral.
This will be my last riddle for a couple of days, as school is very... | CommonCrawl |
1(a) Why separately excited DC motor is widely used as compared to DC shunt motor? Explain.
1(b) Give advantages of regenerative braking of DC motor compared to other methods of braking?
1(c) Explain why V/F control is popular in AC induction motor control.
1(d) Give advantages of high frequency induction heating as co... | CommonCrawl |
Can you believe school has already started? It seems like we were just finishing last semester. Last semester was tough because the administration had a hard time keeping records of all the students in order, which slowed everything down. This year, they are going to be on top of things. They have recognized that you h... | CommonCrawl |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.