Wlodzimierz Holsztynski
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Registered User
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two queens mathematics and death not cheerful not sad guide me through the land pat me on my head they live in my one man nation i follow them to my destination wh, (long ago) polynomials over finite Galois field spread so evenly across their finite affine space i wish for a network of friends to count on wh, 1996-03-05/06 |
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1h |
revised |
Are sums of the inverses of prime siblings finite? cosmetic |
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1h |
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Are sums of the inverses of prime siblings finite? Extra PART II |
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3h |
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Are sums of the inverses of prime siblings finite? @Nilotpal: yes (more or less), is there any gap $d$ greater than or equal $4$ ($d=2$ is for twin primes) between primes for which the sum of the reciprocal primes differing by d is convergent. (Your English is smoother than mine). Thank you. |
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4h |
asked | Are sums of the inverses of prime siblings finite? |
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1d |
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What is barycentric simplicial subdivision? @Heng, I'd say hit the textbooks or Google (perhaps wikipedia, I don't know). |
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1d |
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What is barycentric simplicial subdivision? edited tags |
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1d |
answered | Why is Set, and not Rel, so ubiquitous in mathematics? |
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1d |
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Why is Set, and not Rel, so ubiquitous in mathematics? It took me only a dozen editions to get $\LaTeX$ right above. It still doesn't look pretty but I am not going to beautify it :-) |
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1d |
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Why is Set, and not Rel, so ubiquitous in mathematics? @mbsq: I'll guess and signal a direction toward an answer (I don't know your formalism): $\{f|f:\omega\rightarrow \omega_1\} =\bigcup_{\alpha < \omega_1}\{i_{\alpha\omega_1}\circ(f:\omega\rightarrow\alpha)\}$. (you and OM are killing me with $\LaTeX$. Yes, this is all just a matter of convention--said Alice in Wonderland. |
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1d |
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Why is Set, and not Rel, so ubiquitous in mathematics? typo |
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1d |
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Why is Set, and not Rel, so ubiquitous in mathematics? 2nd part (but the system is acting up) |
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1d |
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Why is Set, and not Rel, so ubiquitous in mathematics? @Qfwfq, there was plenty of (objective) evidence during my years. I'll expand my "Answer" above to reflect it somewhat. -o=o- @mbsq, what you call so cheerfully "absurdity" is the mathematical reality at least since Eilenberg + (Mac Lane, Cartan, Steenrod, Grothendieck, ...), while I am old enough to remember the good set-theoretical, pre-category times. |
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2d |
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Is there a better function (linear or even a projection)? title expansion |
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2d |
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Importance of separability vs. second-countability Isn't thee theorem about separability of the product of continuum many separable spaces due to Edward Szpilrajn-Marczewski? BTW, it holds for the product of $2^a$ spaces with dense subsets of cardinality less or equal $a$. |
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2d |
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Is this cube packing possible? @Dustin, I see only a very weak analogy between the 2d and 3d situations described in your question. What am I missing? |
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2d |
answered | Why is Set, and not Rel, so ubiquitous in mathematics? |
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2d |
revised |
Why is Set, and not Rel, so ubiquitous in mathematics? formatting |
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2d |
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Why is Set, and not Rel, so ubiquitous in mathematics? cosmetics + PS |
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2d |
answered | Why is Set, and not Rel, so ubiquitous in mathematics? |
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May 17 |
revised |
General and translational Birkhoff lattices. Equational classes. some noise removed |
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May 17 |
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General and translational Birkhoff lattices. Equational classes. Thank you Gerhard "web traveler" Paseman. |
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May 16 |
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General and translational Birkhoff lattices. Equational classes. a clearer choice of a word |
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May 16 |
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Germs at infinity of sequence of integers C'mon Andreas, "Balcerzyk" is not such a hard name :-) |
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May 16 |
revised |
General and translational Birkhoff lattices. Equational classes. a more complete description of the goal |
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May 16 |
comment |
Proof that $L^2(0,T;X)^* = L^2(0,T;X^*)$ I am curious: what is what? |
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May 16 |
asked | General and translational Birkhoff lattices. Equational classes. |
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May 16 |
comment |
What are some reasonable-sounding statements that are independent of ZFC? Wow! (Just unbelievable :-). |
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May 16 |
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Can a composition with itself of a universal self-map be non-universal? an equivalent but simpler formula |
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May 16 |
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Easy proof of the fact that isotropic spaces are Euclidean Perhaps someone may fix the typo in (*). |
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May 15 |
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A characterization of Hilbert spaces? @Sergei, your theorem/proof is very-very nice, you had an idea after an idea. |
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May 15 |
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A characterization of Hilbert spaces? @Sergei, somehow I missed your answer, I discovered your answer just a moment ago, I am really sorry. I'll carefully read your answer within 24h, and will comment on it (even if I will not get it :-), but at least I will admit it). |
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May 15 |
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Simplex with edges of length at least s having smallest circumradius Otherwise (if it were complex) I would not be able to provide it :-). You're most welcome. BTW. I introduced this method (most likely very well known?) for some other geometric results in the past. |
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May 15 |
revised |
Simplex with edges of length at least s having smallest circumradius the whole enchilada |
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May 15 |
accepted | Simplex with edges of length at least s having smallest circumradius |
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May 15 |
revised |
Simplex with edges of length at least s having smallest circumradius REMARK |
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May 15 |
revised |
Simplex with edges of length at least s having smallest circumradius details (expansion) |
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May 15 |
revised |
Picturing a Certain Torus and Klein Bottle typo |
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May 15 |
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Simplex with edges of length at least s having smallest circumradius Edges are intervals $(e_j\ e_k)$ for $j\ne k$. |
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May 15 |
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Simplex with edges of length at least s having smallest circumradius You ask for the shortest radius when the edges are long. I look above for the longest minimum of edges when the radius is short. It leads to your question. It's a standard duality for such situations. (And you can always move your simplex to position the center of the sphere at the origin of the space; I'll expand the text of my "Answer" a little later; first let my eyes rest from the $\LaTeX$ struggles and battles from other MO questions. |
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May 15 |
revised |
Picturing a Certain Torus and Klein Bottle 2nd part |
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May 15 |
answered | Picturing a Certain Torus and Klein Bottle |
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May 15 |
answered | Simplex with edges of length at least s having smallest circumradius |
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May 15 |
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Simplex with edges of length at least s having smallest circumradius Wow! Two hours and still no answer?! I better play MO's savior :-) |
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May 14 |
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Research on the structure of a non-Goldbach number? What's the difference between studying non-Goldbach integers and the Goldbach conjecture? (to me--none). |
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May 14 |
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Is it true that Nature promotes products? Oh, it is a mathematical question after all. I read the title, Nature, produce, ... Well, most(?) of us are used to the SET category. And SET is not too symmetric, is not self-dual. |
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May 14 |
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“monotone” homotopy? My instant reflex would be to consider the continuity of $t\mapsto f^{-1}_t(A)$ in the space of closed sets (with the Hausdorff metric) rather than just continuity of the distance for the purpose of the definition of the monotone homotopy. |
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May 13 |
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Can a composition with itself of a universal self-map be non-universal? I apologize for my initial misspellings of Ralph's last name. In my email there were several instances of his name appearing, and each time, when there was a mixture of the lower and upper characters, the letter k/K appeared in the lower case (which I carefully checked before posting my question). Then seeing your @Gerhard "correct spelling" Paseman I trusted you, of course, but checked the state of affairs with Google anyway, and indeed you and Google agree. |
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May 13 |
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Can a composition with itself of a universal self-map be non-universal? @Gerhard "universal" Paseman: I'll expand the text of my "question" to provide a justification of "EXAMPLE" (I'll also try to include the reference to my corresponding "Fund. Math" paper.). About the McKenzie's example, I have an email from him with a pdf attachment. I wish he showed up on MO and told his story himself. I have no qualms to inform the public about his result, but I feel uneasy about writing more about it. |
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May 13 |
revised |
Can a composition with itself of a universal self-map be non-universal? Example explained |
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May 13 |
revised |
Can a composition with itself of a universal self-map be non-universal? cosmetic |
